Foldable device

ABSTRACT

A foldable device includes a flexible display including first, second, and third portions; a body including first, second, and third support portions which respectively supports the first, second, and third portions; a hinge including a first rotation axis which connects the first support portion to the third support portion, and a second rotation axis which connects the second support portion to the third support portion; and a slot hole which is rotatably coupled with the first and second rotation axes, and which moves the first rotation axis and the second rotation axis when the first support portion and the second support portion rotate with respect to the third support portion. The first and second rotation axes allow the first and second support portions to rotate with respect to the third support portion when the flexible display changes from an open state to a closed state.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.15/399,410, filed on Jan. 5, 2017, in the U.S. Patent and TrademarkOffice, which is a continuation-in-part of U.S. application Ser. No.14,952,417, filed on Nov. 25, 2015, in the U.S. Patent and TrademarkOffice, and which claims priority from Korean Patent Application No.10-2015-0088718, filed on Jun. 22, 2015, in the Korean IntellectualProperty Office, Korean Patent Application No. 10-2016-0001703, filed onJan. 6, 2016, in the Korean Intellectual Property Office, and whichclaims the benefit of U.S. Provisional Application No. 62/145,135, filedon Apr. 9, 2015, in the U.S. Patent and Trademark Office, thedisclosures of which are herein incorporated by reference in theirentireties.

BACKGROUND Field

Apparatuses and methods consistent with exemplary embodiments relate toa foldable device including a flexible display.

Description of the Related Art

A portable foldable device (hereinafter, referred to as a mobile device)such as a communication terminal, a game console, a multimedia device, aportable computer, or a photographing apparatus generally includes adisplay device that displays image information and an input unit such asa keypad. Many mobile devices have a foldable structure that may befolded into a smaller size in order to improve the portability thereofIn such mobile devices, two bodies are connected to each other via thefoldable structure. Since a related art display device is not foldable,the display device may be arranged on one of two bodies. Hence, it maydifficult to implement a large display device to a mobile device havinga foldable structure.

Along with the development of a flexible and bendable display device,there have been attempts to implement the display device to a mobiledevice having a foldable structure. In this case, since the flexibledisplay may be arranged over two bodies to cross over the foldablestructure, a large screen may be provided. However, although theflexible display may be bent, if the flexible display is sharply bent,the flexible display may be damaged. Hence, a curved portion having apredetermined curvature is formed at the center of the flexible displaywhen the flexible display folds.

Therefore, the foldable device using a flexible display may need toprovide a structure that accommodates a curved portion of the flexibledisplay while the foldable device is being folded, and may need tosupport the curved portion of the flexible display to be flat while thefoldable device is being unfolded.

SUMMARY

Exemplary embodiments address at least the above problems and/ordisadvantages and other disadvantages not described above. Also, theexemplary embodiments are not required to overcome the disadvantagesdescribed above, and may not overcome any of the problems describedabove.

One or more exemplary embodiments include a foldable device that has asmall size and is portable.

One or more exemplary embodiments include a foldable device on which aflexible display is supported flat when the foldable device unfolds.

One or more exemplary embodiments include a foldable device that mayreduce distortion of a screen when the foldable device unfolds at anobtuse angle.

One or more exemplary embodiments provide a flexible display that maywithstand pressure or damage occurring when the flexible display of thefoldable device is folded.

According to an aspect of an exemplary embodiment, there is provided afoldable device including: a hinge shaft that includes first and secondhinge shafts; a flexible display that includes a first portion, a secondportion, and a third portion between the first portion and the secondportion; a first body that includes a first fixed portion to which thefirst portion is fixed, rotates around the first hinge shaft, and movesbetween a folding position and an unfolding position, and is movable toor from the first hinge shaft; a first support portion that is providedon the first body and moves between a support position and a receivingposition, the support position enabling the first support portion topartially support the third portion, the receiving position enabling thethird portion to be bent to form a curved receiving space in the firstbody; and a restriction unit configured to maintain the first supportportion at the support position when the first body is in a positionbetween the unfolding position and a start point of the receivingposition and allow the first support portion to move to the receivingposition when the first body folds beyond the receiving start position.

The foldable device may further include: a second body that includes asecond fixed portion to which the second portion is fixed, rotatesaround the second hinge shaft, moves between a folding position and anunfolding position, and is movable to or from the second hinge shaft;and a second support portion that is provided on the second body andmoves between a support position and a receiving position, the supportposition enabling the second support portion to partially support thethird portion, the receiving position enabling the third portion to bebent to form a curved receiving space in the second body. Therestriction unit may be configured to maintain the second supportportion at the support position when the second body is in a positionbetween the unfolding position and a start point of the receivingposition and allow the second support portion to move to the receivingposition when the second body folds beyond the receiving start position.The support position enabling the second support portion to partiallysupport the third portion may correspond to the support positionenabling the first support portion to partially support the thirdportion. The receiving position enabling the third portion to be bent toform a curved receiving space in the first body may correspond to thereceiving position enabling the third portion to be bent to form acurved receiving space in the second body.

At the folding position, the first portion and the second portion may belocated closer to each other than at the unfolding position, and faceeach other. The third portion may be bent from the first and secondportions into the first and second bodies and received in the receivingspace in a droplet shape.

The foldable device may further include a first gear portion and asecond gear portion that are respectively provided on the first andsecond hinge shafts and are engaged with each other so that the firstand second bodies synchronously rotate together.

The foldable device may further include a locking unit configured tolock the first body and the second body at least one inclined positionbetween the unfolding position and the folding position. An openingangle between the first body and the second body at the receiving startposition may be equal to or less than an opening angle between the firstbody and the second body at the at least one inclined position.

The restriction unit may include: a first support arm and a secondsupport arm that respectively support the first support portion and thesecond support portion and respectively pivot about fixed positions withrespect to the first hinge shaft and the second hinge shaft; a firstguide pin and a second guide pin that are respectively provided on thefirst support arm and the second support arm; and a first guide slot anda second guide slot that respectively rotate around the first hingeshaft and the second hinge shaft along with the first body and thesecond body, respectively guide the first guide pin and the second guidepin, and include support parts that maintain the first support arm andthe second support arm at a position at which the first support arm andthe second support arm support the first support portion and the secondsupport portion and receiving parts that allow the first support arm andthe second support arm to move away from the first support portion andthe second support portion so that the first support portion and secondsupport portion are allowed to move to the receiving position.

Each of the first support arm and the second support arm may include: afirst link arm that pivots about the fixed position; and a second linkarm having one end portion that is pivotably connected to the first linkarm by the first guide pin or the second guide pin and another endportion that is pivotably connected to the first support portion or thesecond support portion and supports the first support portion or thesecond support portion.

The restriction unit may include: a rotating cam that supports the firstsupport portion and the second support portion and includes a first campath corresponding to the support position and a second cam pathcorresponding to the receiving position; a pinion gear that is connectedto the rotating cam; a rack gear that is engaged with the pinion gear; apulley; and a connection member having one end portion that is connectedto a fixed position with respect to the hinge shaft and another endportion that is connected through the pulley to the rack gear and movesthe rack gear when the first body and the second body fold or unfold.

The connection member may have a strip shape having bending elasticity.

The connection member may include a wire, and the foldable device mayfurther include a return spring that is connected to the rack gear andapplies a tensile force to the wire.

The foldable device may further include a path difference compensatingunit configured to restrict an amount of movement of at least one of thefirst body and the second body to or from the hinge shaft, andcompensate for a path difference between the flexible display and thefirst body and a path difference between the flexible device and thesecond body while the foldable device folds or unfolds.

The path difference compensating unit may be further configured toenable at least one of the first body and the second body to move awayfrom the hinge shaft during a period when the foldable device moves fromthe unfolding position to a changing position and enable at least one ofthe first body and the second body to move toward the hinge shaft duringa period when the foldable device moves from the changing position tothe folding position.

An opening angle between the first and second bodies at the changingposition may be equal to an opening angle between the first and secondbodies at the receiving start position.

The foldable device may further include: a first hinge unit that ispivotably connected to the first hinge shaft and is connected to thefirst body; and a second hinge unit that is pivotably connected to thesecond hinge shaft and is connected to the second body. The first bodyand the second body may be respectively connected to the first hingeunit and the second hinge unit so that the first body and the secondbody respectively move to or from the first hinge shaft and the secondhinge shaft.

The first hinge unit and the second hinge unit may respectively include:a first hinge frame and a second hinge frame that are respectivelyrotatably connected to the first hinge shaft and the second hinge shaft;and a first movable frame and a second movable frame that arerespectively supported on the first hinge frame and the second hingeframe so that the first movable frame and the second movable framerespectively move to or from the first hinge shaft and the second hingeshaft. The first body and the second body are respectively coupled tothe first movable frame and the second movable frame.

The path difference compensating unit may include: a first restrictionpin and a second restriction pin that have fixed positions with respectto the first hinge shaft and the second hinge shaft; and restrictionslots into which the first restriction pin and the second restrictionpin are respectively inserted and that respectively restrict amounts ofmovement of the first body and the second body according to rotationangles of the first body and the second body while the restriction slotspivot along with the first body and the second body.

According to an aspect of another exemplary embodiment, there isprovided a foldable device including: a flexible display that includes afirst portion, a second portion, and a third portion between the firstportion and the second portion; a first body and a second body to whichthe first portion and the second portion are respectively fixed, andthat move between an unfolding position and a folding position at whichthe first portion and the second portion are located closer to eachother that at the unfolding position and face each other and the thirdportion is bent from the first portion and the second portion into thefirst body and the second body and is received in a receiving space in adroplet shape; and a first support portion and a second support portionthat are respectively provided on the first body and the second body tosupport the third portion and are maintained at a support position atwhich the first support portion and the second support portion supportthe third portion when the first body and the second body are in aposition between the unfolding position and a starting point of areceiving position and move to the receiving position at which the firstsupport portion and the second support portion move away from the thirdportion to form the receiving space when the first body and the secondbody fold beyond the receiving start position.

The first body and the second body may respectively rotate about a firsthinge shaft and a second hinge shaft and move between the unfoldingposition and the folding position. The foldable device may furtherinclude a first gear portion and a second gear portion that arerespectively provided on the first hinge shaft and the second hingeshaft and are engaged with each other so that the first body and thesecond body synchronously rotate together.

The foldable device may further include a locking unit configured tolock the first body and the second body at least one inclined positionbetween the unfolding position and the folding position. An openingangle between the first body and the second body at the starting pointof the receiving position may be equal to or less than an opening anglebetween the first body and the second body at the at least one inclinedposition.

The first body and the second body may be respectively movable to orfrom the first hinge shaft and the second hinge shaft.

The foldable device may further include a path difference compensatingunit configured to restrict an amount of movement of at least one of thefirst body and the second body to or from the first hinge shaft and thesecond hinge shaft, and compensate for a path difference between theflexible display and the first body and a path difference between theflexible display and the second body while the foldable device folds orunfolds.

According to an aspect of another exemplary embodiment, there isprovided a foldable device including: a hinge unit including a hingeshaft, a restriction slot, and a restriction pin inserted into therestriction slot; and a body configured to be move between a foldingposition and a unfolding position and connected to the hinge unitthrough the restriction pin; wherein a position of the restriction pinchanges along the restriction slot while the body moves between thefolding position and the unfolding position, wherein the body moves awayfrom the hinge shaft when the body moves from the unfolding position tothe folding position.

According to an aspect of an exemplary embodiment, there is provided afoldable device including: a flexible display including a first portion,a second portion, and a third portion disposed between the first portionand the second portion; a body including a first support portion whichsupports the first portion of the flexible display, a second supportportion which supports the second portion of the flexible display, and athird support portion which supports the third portion of the flexibledisplay; a hinge including a first rotation axis which connects thefirst support portion to the third support portion, and a secondrotation axis which connects the second support portion to the thirdsupport portion, the first rotation axis and the second rotation axisallowing the first support portion and the second support portion torotate with respect to the third support portion when the flexibledisplay changes from an open state to a closed state; and a slot holewhich is disposed on at least one of the first support portion and thethird support portion, and at least one of the second support portionand the third support portion, which is rotatably coupled with the firstrotation axis and the second rotation axis, and which moves the firstrotation axis and the second rotation axis when the first supportportion and the second support portion rotate with respect to the thirdsupport portion.

The third support portion may include a first support wing rotatablyconnected to the first support portion and a second support wingrotatably connected to the second support portion.

The first rotation axis may be disposed on both sides of the firstsupport wing, the second rotation axis may be disposed on both sides ofthe second support wing, and the slot hole may include a first slot holedisposed on the first support portion to receive the first rotation axisof the first support wing and a second slot hole disposed on the secondsupport portion to receive the second rotation axis of the secondsupport wing.

The first and second slot holes may have a shape of a straight line.

The slot hole may include a first slot hole disposed on both sides ofthe first support wing and a second slot hole disposed on both sides ofthe second support wing. The first rotation axis may be disposed on thefirst support portion and inserted to the first slot hole of the firstsupport wing, and the second rotation axis may be disposed on the secondsupport portion and inserted to the second slot hole of the secondsupport wing.

The first and second slot holes may have a curved shape.

The slot hole may include a first slot hole disposed on both sides ofthe first support wing, a second slot hole disposed on both sides of thesecond support wing, a third slot hole disposed on the first supportportion which faces the first slot hole of the first support wing, and afourth slot hole disposed on the second support portion which faces thesecond slot hole of the second support wing. The first rotation axis maybe inserted to the first slot hole of the first support wing and thethird slot hole of the first support portion, and the second rotationaxis may be inserted to the second slot hole of the second support wingand the fourth slot hole of the second support portion.

A fixing member which fixes a third portion of the flexible display maybe fixed on an upper surface of the first and second support wings.

The fixing member may include a double-sided tape and an adhesive.

The foldable device may further include: a first reinforcing plate thatcovers a part of the first support portion and the third supportportion, and supports a part of the flexible display; and a secondreinforcing plate that covers a part of the second support portion andthe third support portion, and supports a part of the flexible display.

The first and second reinforcing plates may be fixed on a rear surfaceof the flexible display.

The foldable device may further include: first and second guide slotsand first and second support arms which allow the first and secondsupport wings to move, according to movement of the first and secondsupport portions, between a support position which supports that thethird portion of the flexible display is in the same plane as the firstand second portions, and a receiving position which forms a receivingspace to receive a curved third portion of the flexible display betweenthe first and second support portions.

The first and second guide slots may move along with the first andsecond support portions and the first and second support arms may moveby the first and second guide slots.

The first and second support arms may include first and second guidepins which pass through the first and second guide slots and areextended to a bottom of the first and second support wings.

The third support portion may further include a central support memberwhich supports a central portion of the third portion of the flexibledisplay.

According to an aspect of another exemplary embodiment, there isprovided a foldable device including: a flexible display including afirst portion, a second portion, and a third portion disposed betweenthe first portion and the second portion; a body including a firstsupport portion which supports the first portion of the flexibledisplay, a second support portion which supports the second portion ofthe flexible display, and a third support portion which supports thethird portion of the flexible display; a hinge including a firstrotation axis which connects the first support portion to the thirdsupport portion, a second rotation axis which connects the secondsupport portion to the third support portion, the first rotation axisand the second rotation axis allowing the first support portion and thesecond support portion to rotate with respect to the third supportportion when the flexible display changes from an open state to a closedstate; and a movement restriction member that moves a part of the thirdportion of the flexible display along with the third support portionwhen the flexible display changes from the open state to the closedstate.

The third support portion may include a first support wing rotatablyconnected to the first support portion and a second support wingrotatably connected to the second support portion.

The movement restriction member may include: a plurality of slot groovesdisposed on upper surfaces of each of the first and second supportwings; and a sliding gel which is received in the plurality of slotgrooves and slidably moves the third portion of the flexible displaywhile the third portion is attached to upper surfaces of the first andsecond support wings.

The sliding gel may include a lubricating oil and grease.

The movement restriction member may include: a first stiffener which isfixed on a rear side of a part of the third portion of the flexibledisplay corresponding to the first support wing; and a second stiffenerwhich is fixed on a rear side of a part of the third portion of theflexible display corresponding to the second support wing.

According to an aspect of another exemplary embodiment, there isprovided a foldable device including: a flexible display including afirst portion and a second portion which face each other when theflexible display is folded, and a third portion disposed between thefirst portion and the second portion; a support wing disposed below andfixed to the third portion of the flexible display; and a support platethat is integrated with the support wing, is disposed between the firstportion and the third portion, and has a slot hole to which a rotationaxis is inserted, wherein when the flexible display is folded, the slothole moves toward the first portion along with the rotation axis.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other aspects will be more apparent by describingcertain exemplary embodiments, taken with reference to the accompanyingdrawings, in which:

FIG. 1 is a perspective view illustrating an outer appearance of afoldable device according to an exemplary embodiment;

FIG. 2 is a side view illustrating an unfolding state of the foldabledevice of FIG. 1 according to an exemplary embodiment;

FIG. 3 is a side view illustrating a folding state of the foldabledevice of FIG. 1 according to an exemplary embodiment;

FIG. 4 is a cross-sectional view of a flexible display according to anexemplary embodiment;

FIGS. 5A and 5B are schematic views illustrating a folding state of thefoldable device at an angle of, for example, 90°;

FIG. 6 is a schematic exploded perspective view of the foldable deviceaccording to an exemplary embodiment;

FIG. 7 is an exploded perspective view of the foldable device of FIG. 6according to an exemplary embodiment;

FIG. 8 is an exploded perspective view of a hinge unit according to anexemplary embodiment;

FIG. 9 is a side view for explaining an operation of a locking unit;

FIGS. 10A, 10B, and 10C are schematic views of a structure in whichfirst and second bodies move to or from first and second hinge shaftsaccording to an exemplary embodiment, respectively illustrating a statewherein the first and second bodies are unfolded, a state wherein thefirst and second bodies are spaced apart by a maximum distance from thefirst and second hinge shafts, and a state wherein the first and secondbodies are folded;

FIG. 10D is a graph showing a movement distance according to a foldingangle between the first and second bodies in the structure of FIG. 10A;

FIGS. 11A, 11B, and 11C are schematic views of a structure in which thefirst and second bodies move to or from the first and second hingeshafts according to an exemplary embodiment, respectively illustrating astate wherein the first and second bodies are unfolded, a state whereinthe first and second bodies are spaced apart by a maximum distance fromthe first and second hinge shafts, and a state wherein the first andsecond bodies are folded;

FIG. 11D is a graph showing a movement distance according to a foldingangle between the first and second bodies in the structure of FIG. 11A;

FIG. 12A is an exploded perspective view for explaining a connectionrelationship between a first restriction pin and a first restrictionslot according to an exemplary embodiment;

FIG. 12B is a cross-sectional view taken along line E-E′ of FIG. 12A;

FIG. 13 is a schematic view of a restriction unit according to anexemplary embodiment;

FIG. 14 is an exploded perspective view of a structure in which firstand second support arms are pivotably supported according to anexemplary embodiment;

FIG. 15 is a schematic view of the restriction unit including two linkarms according to an exemplary embodiment;

FIGS. 16A, 16B, and 16C are schematic views of the restriction unitaccording to another exemplary embodiment;

FIG. 17 is an exploded perspective view of a structure that moves amovable support member between a first position and a second positionaccording to an exemplary embodiment; and

FIGS. 18A and 18B are cross-sectional views taken along line F-F′ ofFIG. 17, respectively illustrating a state wherein the movable supportmember is located at the second position and a state wherein the movablesupport member is located at the first position;

FIG. 19 is a perspective view of an unfolding state of the foldabledevice according to another exemplary embodiment;

FIG. 20 is a schematic side view of a relationship between a flexibledisplay and a fixed position of a main body in the foldable deviceaccording to another exemplary embodiment;

FIG. 21 is a schematic side view of a folding state of the foldabledevice of FIG. 20;

FIG. 22 is a view of a case where operation of the flexible displaysupported by the supporting wings in the foldable device is notrestricted.

FIG. 23 is an exploded perspective view of a state where the flexibledisplay is separated from the foldable device according to anotherexemplary embodiment;

FIG. 24 is an exploded perspective view of a state where the supportportion is disassembled from the foldable device of FIG. 23;

FIG. 25 is an exploded perspective view of a hinge unit used for thefoldable device of FIG. 23;

FIG. 25A is a perspective view of a fixed hinge of the hinge unit andthe first and second restriction slots of FIG. 23;

FIG. 25B is a perspective view of a locking member of the hinge unit andthe first and second support arms of FIG. 23;

FIG. 25C is a perspective view of a state where the second support armof the hinge unit of FIG. 23 is installed in the second hinge frame andsupports the second support wing;

FIG. 26 is a partial perspective view of a relation between the hingeunit and the support wing in the foldable device according to anotherexemplary embodiment;

FIG. 27 is an exploded rear perspective view of supporting wingsseparated from the first body of the foldable device according toanother exemplary embodiment;

FIG. 28A is a view of a relation between supporting wings and a guidepin, when the foldable device is in an unfolding state;

FIG. 28B is a view of a relation between supporting wings and a guidepin, when the foldable device is in a folding state;

FIG. 29A is a view of a relation between supporting wings and a guidepin, when the foldable device is in an unfolding state according tostill another exemplary embodiment;

FIG. 29B is a view of a relation between supporting wings and a guidepin, when the foldable device is in a folding state according to stillanother exemplary embodiment;

FIGS. 30A and 30B are views of a case where a reinforcing plate on arear side of the flexible display;

FIG. 31A is a view of a case where a curve corresponding to a radius ofcurvature of the flexible display is formed only on supporting wings;

FIG. 31B is a view of a case where a curve corresponding to a radius ofcurvature of the flexible display is formed on a part of the body wheresupporting wings are installed and the supporting wings;

FIG. 32 is a view of an example of a display restriction member of thefoldable device according to another exemplary embodiment;

FIG. 33 is a view of another example of a display restriction member ofthe foldable device according to another exemplary embodiment;

FIG. 34 is a partial sectional view indicating a state that a centralsupport member supports the flexible display while the foldable deviceaccording to another exemplary embodiment is unfolded;

FIG. 35 is a partial sectional view indicating a state of the centralsupport member, while the foldable device is being folded by anotherexemplary embodiment;

FIG. 36 is a perspective view indicating the central support member ofthe foldable device according to another exemplary embodiment; and

FIG. 37 is a view of another example of installation of a rotationalaxis and slot hole of the foldable device according to another exemplaryembodiment.

DETAILED DESCRIPTION

Exemplary embodiments are described in greater detail below withreference to the accompanying drawings.

In the following description, like drawing reference numerals are usedfor like elements, even in different drawings. The matters defined inthe description, such as detailed construction and elements, areprovided to assist in a comprehensive understanding of the exemplaryembodiments. However, it is apparent that the exemplary embodiments canbe practiced without those specifically defined matters. Also,well-known functions or constructions are not described in detail sincethey would obscure the description with unnecessary detail.

As used herein, the term “and/or” includes any and all combinations ofone or more of the associated listed items. Expressions such as “atleast one of” when preceding a list of elements, modify the entire listof elements and do not modify the individual elements of the list.

FIG. 1 is a perspective view illustrating an outer appearance of afoldable device according to an exemplary embodiment. FIG. 2 is a sideview illustrating an unfolding state of the foldable device of FIG. 1according to an exemplary embodiment. FIG. 3 is a side view illustratinga folding state of the foldable device of FIG. 1 according to anexemplary embodiment.

Referring to FIGS. 1 through 3, the foldable device may include firstand second bodies 1 and 2 and a flexible display 4. The first and secondbodies 1 and 2 are connected to each other and may move between anunfolding position of FIG. 2 and a folding position of FIG. 3.

FIG. 4 is a cross-sectional view of the flexible display 4 according toan exemplary embodiment. Referring to FIG. 4, the flexible display 4 mayinclude a flexible display panel 41 that displays an image and atransparent protective panel 43 that is disposed on the flexible displaypanel 41. An additional panel or substrate may be disposed between thetransparent protective panel 43 and the flexible display panel 41. Theflexible display panel 41 may be, for example, an organic light-emittingdiode (OLED) panel. When the flexible display panel 41 is an OLED panel,an organic emission layer may be disposed between an upper substrate anda lower substrate. A polarization plate may be disposed on the uppersubstrate from which light is emitted. Also, the flexible display 4 mayfurther include a touch panel 42 as an input unit. For example, thetouch panel 42 may be disposed between the transparent protective panel43 and the flexible display panel 41. The flexible display panel 41, thetouch panel 42, and the transparent protective panel 43 may be adheredto one another by using an optically-clear adhesive (OCA) layer.However, the present exemplary embodiment is not limited thereto, andthe flexible display 4 may further include any of various other opticalpanels or optical films.

The flexible display 4 is partially fixed to the first body 1 and thesecond body 2. The flexible display 4 may be divided into a firstportionportion 4 a that is fixed to the first body 1, a second portion 4b that is fixed to the second body 2, and a third portion 4 c that isformed between the first body 1 and the second body 2. The first body 1includes a first fixed portion 1 a to which the first portion 4 a isfixed, and the second body 2 includes a second fixed portion 2 a towhich the second portion 4 b is fixed. For example, the first portion 4a and the second portion 4 b of the flexible display 4 may berespectively fixed to the first fixed portion 1 a and the second fixedportion 2 a by using an adhesive unit such as an adhesive or adouble-sided tape. Alternatively or additionally, the first portion 4 aand the second portion 4 b be may respectively fixed to the first fixedportion 1 a and the second fixed portion 2 b through an interference fitor a press fit. In other words, fastening between the first portion 4 aand the first fixed portion 1 a may be achieved by friction after thefirst portion 4 a and the first fixed portion 1 a are pushed together.Similarly, fastening between the second portion 4 b and the second fixedportion 2 b may be achieved by friction after the second portion 4 b andthe second fixed portion 2 b are pushed together. The third portion 4 cof the flexible display 4 may not be fixed to the first body 1 or thesecond body 2. That is, the third portion 4 c may not be adhered to thefirst and second bodies 1 and 2. When the first and second bodies 1 and2 are located at the folding position of FIG. 3, the third portion 4 cforms a curved portion 4d having a predetermined radius of curvature.Accordingly, since the flexible display 4 may not be sharply bent andthe third portion 4 c is bent by forming the curved portion 4d or isspread, the first and second bodies 1 and 2 may change between thefolding position and the unfolding position. Also, when the foldabledevice folds, since the flexible display 4 may be received in areceiving space 3 in the first and second bodies 1 and 2, the foldabledevice may have a compact size and may be easily carried. That is, whenthe foldable device of the present exemplary embodiment folds, the firstportion 4 a and the second portion 4 b of the flexible display 4 arelocated close to each other to face each other. At the same time, thethird portion 4 c may be bent from the first and second portions 4 a and4 b into the first and second bodies 1 and 2 and is received in thereceiving space 3 to have a droplet shape. Hence, the foldable devicemay have a compact size when the foldable device folds.

The first and second bodies 1 and 2 may be connected to each other. Theposition of the first and second bodies 1 and 2 may change between theunfolding position and the folding position due to a hinge unit 5. Forexample, the hinge unit 5 may include hinge shafts. The hinge shafts ofthe present exemplary embodiment may include first and second hingeshafts 5 a-1 and 5 a-2 that are spaced apart from each other in alongitudinal direction L. The first and second bodies 1 and 2 mayrespectively rotate about the first and second hinge shafts 5 a-1 and 5a-2 to change between the unfolding position and the folding position.

The foldable device may be a portable mobile device such as acommunication terminal, a game console, a multimedia device, a portablecomputer, or a photographing apparatus. The present exemplary embodimentis not limited thereto, and the foldable device may be any device aslong as it includes the first body 1 to which the first portion 4 a ofthe flexible display 4 is fixed and the second body 2 to which thesecond portion 4 b of the flexible display 4 is fixed and that isfoldably connected to the first body 1.

A processing unit and input/output units for performing functionsaccording to the use of the foldable device may be provided on the firstand second bodies 1 and 2. When the foldable device is a multimediaterminal that provides images and music, the processing unit may includean image information processing unit and an audio information processingunit. When the foldable device is a communication terminal, theprocessing unit may include a communication module. The input/outputunits may include an image input/output unit, an audio input/outputunit, and a manipulation unit for user manipulation. The manipulationunit may be realized by using the touch panel 42 of the flexible display4.

FIGS. 5A and 5B are schematic views illustrating a state wherein thefoldable device is folded at an angle of, for example, 90°. Referring toFIGS. 5A and 5B, there is a difference (hereinafter, referred to as afolding/unfolding path difference) between a folding/unfolding path ofthe first and second bodies 1 and 2 and a folding/unfolding path of theflexible display 4 when the first and second bodies 1 and 2 arefolded/unfolded. For example, assuming that the flexible display 4 isentirely fixed to the first and second bodies 1 and 2, when the firstand second bodies 1 and 2 fold at an angle of 90°, the third portion 4 cis bent at a right angle as marked by a dashed line 4 e in FIG. 5A. Inthis case, the folding/unfolding path difference is “0”.

However, when the flexible display 4 is sharply bent, the flexibledisplay 4 may be permanently deformed or may lose its function.Accordingly, in order for the flexible display 4 to be smoothly bentduring a folding/unfolding process, the third portion 4 c of theflexible display 4 is not fixed to the first and second bodies 1 and 2.In this case, the third portion 4 c of the flexible display 4 may havean arc shape having a radius of curvature R as marked by a solid line 4f in FIG. 5A due to its elasticity. A length difference 4 g between aportion corresponding to the dashed line 4 e and a portion correspondingto the solid line 4 f is the folding/unfolding path difference. Thefolding/unfolding path difference may be presented as 2R-2πR/4.Hereinafter, the folding/unfolding path difference is denoted byreference numeral 4 g. If the second portion 4 b of the flexible display4 is fixed to the second body 2 and the first portion 4 a of theflexible display 4 is not fixed to the first body 1, the flexibledisplay 4 is pushed toward an end portion of the first body 1 by as muchas the folding/unfolding path difference 4g. Accordingly, the thirdportion 4 c of the flexible display 4 may be smoothly bent inward asmarked by the solid line 4 f.

If the first and second portions 4 a and 4 b of the flexible display 4are respectively fixed to the first and second bodies 1 and 2, the thirdportion 4 c of the flexible display 4 is bent both inward and outwardand thus an uneven portion 4 h is formed as shown in FIG. 5B. The unevenportion 4 h may cause the flexible display 4 to be permanently deformed.Also, when the first and second bodies 1 and 2 are used at an openingangle ranging from, for example, about 90° to about 180°, distortion ofa screen may occur at the uneven portion 4 h. Also, when the thirdportion 4 c is repeatedly bent inward and outward, the flexible display4 may be permanently deformed or damaged at the uneven portion 4 h.

A length of the first body 1 may be extended by as much as thefolding/unfolding path difference 4 g so that the first body 1 has anextended portion and the first portion 4 a of the flexible display 4 mayslide along the first body 1. However, in this case, when the first andsecond 1 and 2 completely unfold, the extended portion of the first body1 may not be covered by the flexible display 4.

According to an exemplary embodiment, at least one of the first andsecond bodies 1 and 2 may move to or from the first and second hingeshafts 5 a-1 and 5 a-2 to compensate for the folding/unfolding pathdifference 4 g during a folding/unfolding process. For example, when thefirst and second bodies 1 and 2 fold, the first and second bodies 1 and2 may move away from the first and second hinge shafts 5 a-1 and 5 a-2.As the third portion 4 c of the flexible display 4 forms the curvedportion 4 d and is received in the receiving space 3 in the first andsecond bodies 1 and 2, the first and second bodies 1 and 2 may movetoward the first and second hinge shafts 5 a-1 and 5 a-2. When the firstand second bodies 1 and 2 unfold, the first and second bodies 1 and 2may move away from the first and second hinge shafts 5 a-1 and 5 a-2. Asthe curved portion 4 d of the third portion 4 c of the flexible display4 unfolds and is separated from the receiving space 3 in the first andsecond bodies 1 and 2, the first and second bodies 1 and 2 may moveagain toward the first and second hinge shafts 5 a-1 and 5 a-2.Accordingly, in order to compensate for the folding/unfolding pathdifference 4 g during the folding/unfolding process, the foldable devicemay include a path difference compensating unit that restricts an amountof movement of the first and second bodies 1 and 2 to or from the firstand second hinge shafts 5 a-1 and 5 a-2. The path differencecompensating unit may enable at least one of the first and second bodies1 and 2 to move away from the first and second hinge shafts 5 a-1 and 5a-2 during a period when the foldable device moves from the unfoldingposition to a changing position. The path difference compensating unitmay enable at least one of the first and second bodies 1 and 2 to movetoward the first and second hinge shafts 5 a-1 and 5 a-2 during a periodwhen the foldable device moves from the changing position to the foldingposition. The changing position may be the same as a receiving startposition of first and second support portions 1 b and 2 b which will beexplained below. In other words, an opening angle between the first andsecond bodies 1 and 2 at the changing position may be equal to or lessthan an opening angle between the first and second bodies 1 and 2 at thereceiving start position. The path difference compensating unit will beexplained below in detail.

Referring to FIGS. 2 and 3, the first and second support portions 1 band 2 b that partially support the third portion 4 c of the flexibledisplay 4 at the unfolding position may be respectively provided on thefirst and second bodies 1 and 2. When the first and second bodies 1 and2 are located at the folding position, the first and second supportportions 1 b and 2 b pivot to a position at which the receiving space 3in which the curved portion 4d is received is formed in the first andsecond bodies 1 and 2. In this configuration, the flexible display 4 maybe supported flat at the unfolding position, and may be received with acompact size in the first and second bodies 1 and 2 at the foldingposition.

The first and second support portions 1 b and 2 b may be maintained at asupport position (see FIG. 2) at which the first and second supportportions 1 b and 2 b partially support the third portion 4 c of theflexible display 4 when an angle between the first and second bodies 1and 2 ranges from 180° to a receiving start angle (of the receivingstart position), and may pivot to a receiving position (see FIG. 3) atwhich the receiving space 3 is formed when the angle between the firstand second bodies 1 and 2 is less than the receiving start angle. Sincethe foldable device is rarely used when the angle between the first andsecond bodies 1 and 2 is less than 90°, the receiving start angle maybe, for example, about 90°. However, the present exemplary embodiment isnot limited thereto, and the receiving start angle may be slightlygreater or less than 90°. In order to stably support the flexibledisplay 4 at an inclined position which will be explained below, thereceiving start angle may be equal to or less than an opening angle atthe inclined position.

FIG. 6 is a schematic exploded perspective view of the foldable deviceaccording to an exemplary embodiment. FIG. 7 is an exploded perspectiveview of the foldable device of FIG. 6 according to an exemplaryembodiment. FIG. 8 is an exploded perspective view of the hinge unit 5according to an exemplary embodiment. Since the hinge unit 5 issymmetric in a width direction W of the foldable device, only one sideof the hinge unit 5 in the width direction W is illustrated in FIG. 8.

Referring to FIGS. 6, 7, and 8, the hinge unit 5 includes a fixed hinge53 including the first and second hinge shafts 5 a-1 and 5 a-2. Thefixed hinge 5-3 is located at a fixed position without rotating ormoving, The first and second bodies 1 and 2 may move to or from thefixed hinge 5-3 and may rotate around the fixed hinge 5-3. The hingeunit 5 may further include a first hinge unit 5-1 that pivots about thefirst hinge shaft 5 a-1 and a second hinge unit 5-2 that pivots aboutthe second hinge shaft 5 a-2. The fixed hinge 5-3 includes the first andsecond hinge shafts 5 a-1 and 5 a-2. The fixed hinge 5-3 may furtherinclude a shielding plate 5 a-3. The first and second hinge shafts 5 a-1and 5 a-2 may be supported on the shielding plate 5 a-3. The first andsecond hinge shafts 5 a-1 and 5 a-2 may be integrally formed with theshielding plate 5 a-3. The shielding plate 5 a-3 is located on a sideportion of the flexible display 4 in the width direction W and covers agap between an end portion of the flexible display 4 in the widthdirection W and the first and second bodies 1 and 2. Accordingly, theinside of the foldable device may be prevented from being exposedthrough the gap and foreign materials may be prevented from beingintroduced into the foldable device through the gap.

The first body 1 is connected to the first hinge unit 5-1 and the secondbody 2 is connected to the second hinge unit 5-2. The first body 1includes a first lower case 1-1 and a first upper case 1-2. The firstupper case 1-2 includes the first fixed portion 1 a and the firstsupport portion 1 b. The first support portion 1 b is coupled to thefirst upper case 1-2 so that the first support portion 1 b pivotsbetween the support position and the receiving position. The second body2 includes a second lower case 2-1 and a second upper case 2-2. Thesecond upper case 2-2 includes the second fixed portion 2 a and thesecond support portion 2b. The second support portion 2 b is coupled tothe second upper case 2-2 so that the second support portion 2 b pivotsbetween the support position and the receiving position.

Referring to FIG. 8, the first hinge unit 5-1 includes a first hingeframe 51-1. The first hinge shaft 5 a-1 is inserted into first slotholes 51-1 a that are formed in the first hinge frame 51-1. A diameterof each of the first slot holes 511 a is determined so that the firsthinge frame 51-1 pivots about the first hinge shaft 5 a-1. Accordingly,the first hinge frame 51-1 may pivot about the first hinge shaft 5 a-1.

A first movable frame 52-1 is supported on the first hinge frame 51-1 sothat the first movable frame 52-1 moves to or from the first hinge shaft5 a-1. For example, a first guide shaft 53-1 that extends in thelongitudinal direction L is provided on the first hinge frame 51-1, andthe first movable frame 52-1 is slidably supported on the first guideshaft 53-1. The first lower case 1-1 and the first upper case 1-2 may becoupled to the first movable frame 52-1 to be respectively disposedunder and over the first movable frame 52-1. According to anotherexemplary embodiment, one of the first lower case 1-1 and the firstupper case 1-2 may be coupled to the first movable frame 52-1 and theother case. The first body 1 is connected to the first hinge unit 5-1 sothat the first body 1 moves to or from the first hinge shaft 5 a-1.

The second hinge unit 5-2 includes a second hinge frame 51-2. The secondhinge shaft 5 a-2 is inserted into second slot holes 51-2 a that areformed in the second hinge frame 51-2. A diameter of each of the secondslot holes 512 a is determined so that the second hinge frame 51-2pivots about the second hinge shaft 5 a-2. Accordingly, the second hingeframe 51-2 may pivot about the second hinge shaft 5 a-2.

A second movable frame 52-2 is supported on the second hinge frame 51-2so that the second movable frame 52-2 moves to or from the second hingeshaft 5 a-2. For example, a second guide shaft 53-2 that extends in thelongitudinal direction L is provided on the second hinge frame 51-2, andthe second movable frame 52-2 is slidably supported on the second guideshaft 53-2. The second lower case 2-1 and the second upper case 2-2 maybe coupled to the second movable frame 52-2 to be respectively disposedunder and over the second movable frame 52-2. Accordingly to anotherexemplary embodiment, one of the second lower case 2-1 and the secondupper case 2-2 may be coupled to the second movable frame 52-2 and theother case. The second body 2 is connected to the second hinge unit 5-2so that the second body 2 moves to or from the second hinge shaft 5 a-2.

First and second gear portions 51-1 b and 51-2 b having at the centerthe first and second slot holes 51-1 a and 51-2 a are respectivelyprovided on the first and second hinge frames 51-1 and 51-2. The firstand second gear portions 511 b and 51-2 b are engaged with each other.In this configuration, the first and second bodies 1 and 2 maysynchronously rotate about the first and second hinge shafts 5 a-1 and 5a-2.

The foldable device may include a locking unit that locks the first andsecond bodies 1 and 2 at any of a plurality of positions. For example,the locking unit may lock the first and second bodies 1 and 2 at theunfolding position (see FIG. 2) and at the folding position (see FIG.3). The locking unit may further lock the first and second bodies 1 and2 at a position (inclined position) having a predetermined opening anglebetween the unfolding position (see FIG. 2) and the folding position(see FIG. 3). The opening angle at the inclined position may be greaterthan 90°. The locking unit may lock the first and second bodies 1 and 2at any of a plurality of inclined positions having an opening anglebetween 180° and 90°. An opening angle of an inclined position may be,for example, 120°.

FIG. 8 illustrates the locking unit according to an exemplaryembodiment. FIG. 9 is a side view for explaining an operation of thelocking unit. Referring to FIGS. 8 and 9, the locking unit may include alocking member 5 c that is located at a fixed position, and a protrusionmember that is fixed by the locking member 5 c while rotating along withthe first and second bodies 1 and 2. The locking member 5 c may includelocking portions 5 c-1, 5 c-2, and 5 c-3 that respectively lock thefirst and second bodies 1 and 2 at the unfolding position, the inclinedposition, and the folding position. The protrusion member may includefirst and second protrusion members 54-1 and 54-2 that are selectivelyfixed by the locking portions 5 c-1, 5 c-2, and 5 c-3 according to anopening angle between the first and second bodies 1 and 2.

The locking member 5 c is located at the fixed position. The lockingmember 5 c is provided on the fixed hinge 5-3. The locking member 5 cmay be fixed to the first and second hinge shafts 5 a-1 and 5 a-2. Inthe present exemplary embodiment, the first and second hinge shafts 5a-1 and 5 a-2 pass through slot holes 5 c-4 that are formed in thelocking member 5 c. Accordingly, the locking member 5 c has the fixedposition with respect to the first and second hinge shafts 5 a-1 and 5a-2.

The first and second protrusion members 54-1 and 54-2 rotate about thefirst and second hinge shafts 5 a-1 and 5 a-2 along with the first andsecond bodies 1 and 2. The first and second protrusion members 54-1 and54-2 are supported on the first and second hinge frames 51-1 and 51-2 sothat the first and second protrusion members 54-1 and 54-2 move towardor away from the locking member 5c. First and second elastic members55-1 and 55-2 apply elastic forces to the first and second protrusionmembers 54-1 and 54-2 to hold the movement of the first and secondprotrusion members 54-1 and 54-2 at the locking portions 5 c-1, 5 c-2,and 5 c-3. In the present exemplary embodiment, the first and secondprotrusion members 54-1 and 54-2 are fixed to the first and second guideshafts 53-1 and 53-2. The first and second guide shafts 53-1 and 53-2are supported on the first and second hinge frames 51-1 and 51-2 so thatthe first and second guide shafts 53-1 and 53-2 slide toward or awayfrom the locking member 5 c.

Since the first and second bodies 1 and 2 synchronously rotate due tothe first and second gear portions 51-2 a and 51-2 b in the presentexemplary embodiment, only one of the first and second bodies 1 and 2may need to be locked. Accordingly, once one of the first and secondprotrusion members 54-1 and 54-2 is fixed by the locking portions 5 c-1,5 c-2, and 5 c-3, the first and second bodies 1 and 2 may be locked notto rotate.

Referring to FIG. 9, when the first and second bodies 1 and 2 arelocated at the unfolding position, the second protrusion member 54-2 isfixed or locked by the locking portion 5 c-1. Since the first and secondbodies 1 and 2 synchronously rotate due to the first and second gearportions 51-2 a and 51-2 b as described above, once the second body 2 islocked at the unfolding position, the first body 1 is also locked at theunfolding position.

When the first and second bodies 1 and 2 begin to fold, the secondprotrusion member 54-2 is pushed in a direction that is opposite to adirection in which an elastic force of the second elastic member 55-2 isapplied and thus is separated from the locking portion 5 c-1. When thefirst and second bodies 1 and 2 reach the inclined position, forexample, a position having an opening angle of 120°, the firstprotrusion member 54-1 is fixed by the locking portion 5 c-2.Accordingly, the first and second bodies 1 and 2 are locked at theinclined position.

When the first and second bodies 1 and 2 continuously move to be folded,the first protrusion member 54-1 is pushed in a direction that isopposite to a direction in which an elastic force of the first elasticmember 55-1 is applied and thus is separated from the locking portion 5c-2. When the first and second bodies 1 and 2 reach the foldingposition, the movement of the first and second protrusion members 54-1and 54-2 are stopped and locked by one pair of locking portions 5 c-3.Accordingly, the first and second bodies 1 and 2 are locked at thefolding position.

As such, since the foldable device may be locked at the unfoldingposition and the folding position, convenience in use and portabilitymay be improved. Also, since the foldable device may be located at apredetermined inclination angle, convenience in use may be furtherimproved. Although the locking member 5 c including one locking portion5 c-2 corresponding to an inclination angle is provided in the presentexemplary embodiment, two or more locking portions 5 c-2 correspondingto two or more inclination angles may be provided, and thus the foldabledevice may be located at positions having the two or more inclinationangles.

As described above, amounts of movement of the first and second bodies 1and 2 to or from a hinge shaft, for example, the first and second hingeshafts 5 a-1 and 5 a-2 are restricted during a folding/unfolding processin order to compensate for the folding/unfolding path difference 4 g. Tothis end, the foldable device includes the path difference compensatingunit. The path difference compensating unit enables at least one of thefirst and second bodies 1 and 2 to move away from the hinge shaft duringa period when the foldable device moves from the unfolding position tothe changing position. The path difference compensating unit enables atleast one of the first and second bodies 1 and 2 to move toward thehinge shaft during a period when the foldable device moves from thechanging position to the folding position.

For example, the path difference compensating unit may include arestriction pin that has a fixed position with respect to the first andsecond hinge shafts 5 a-1 and 5 a-2 and a restriction slot that rotatesabout and moves to or from the first and second hinge shafts 5 a-1 and 5a-2 along with the first and second bodies 1 and 2. The restriction pinstays fixed and does not rotate around the first and second hinge shafts5 a-1 and 5 a-2. The restriction slot is shaped to restrict amounts ofmovement of the first and second bodies 1 according to a rotation angleof the first and second bodies 1 and 2.

FIGS. 10A, 10B, and 10C are schematic views of a structure of a hingeshaft 5 a including the first and second bodies 1 and 2 that move to orfrom the first and second hinge shafts 5 a-1 and 5 a-2 according to anexemplary embodiment. FIG. 10A illustrates a state wherein the first andsecond bodies 1 and 2 are unfolded, FIG. 10B illustrates a state whereinthe first and second bodies 1 and 2 are spaced apart by a maximumdistance from the first and second hinge shafts 5 a-1 and 5 a-2, andFIG. 10C illustrates a state wherein the first and second bodies 1 and 2are folded. In the foldable device according to the present exemplaryembodiment, the first and second bodies 1 and 2 move to or from thefirst and second hinge shafts 5 a-1 and 5 a-2. In FIGS. 10A, 10B, and10C, the flexible display 4 is not shown. FIG. 10D is a graph showing amovement distance according to a folding angle between the first andsecond bodies 1 and 2.

Referring to FIG. 10A, the first and second bodies 1 and 2 may movealong the first and second guide shafts 53-1 and 53-2 as describedabove. Amounts of movement of the first and second bodies 1 and 2 arerestricted by the path difference compensating unit. The path differencecompensating unit may include first and second restriction pins 5 b-1and 5 b-2 having fixed positions, and first and second restriction slots1 c and 2 c that rotate and move along with the first and second bodies1 and 2. For example, the first and second restriction slots 1 c and 2 cmay be formed in the first and second bodies 1 and 2 or the first andsecond movable frames 52-1 and 52-2 (see FIG. 8). The first and secondrestriction pins 5 b 1 and 5 b-2 are respectively inserted into thefirst and second restriction slots 1 c and 2 c. The first and secondrestriction slots 1 c and 2 c respectively include first end portions 1c-1 and 2 c-1 and second end portions 1 c-2 and 2 c-2. At the unfoldingposition, the first and second restriction pins 5 b-1 and 5 b-2 arerespectively located in the first end portions 1 c-1 and 2 c-1, and atthe folding position, the first and second restriction pins 5 b-1 and 5b-2 are respectively located in the second end portions 1 c-2 and 2 c-2.As shown in FIG. 10A, each of the first and second restriction slots 1 cand 2 c linearly extends in a direction that is perpendicular to thelongitudinal direction L of the first and second bodies 1 and 2, and issymmetric with respect to a line X1 that connects the first and secondhinge shafts 5 a-1 and 5 a-2. In this configuration, a movement distanceof the first and second bodies 1 and 2 to or from the first and secondhinge shafts 5 a-1 and 5 a-2 when the first and second bodies 1 and 2fold/unfold is symmetric about an angle of 90° as shown in the graph ofFIG. 10D.

When the first and second bodies 1 and 2 are completely unfolded asshown in FIG. 10A, the folding/unfolding path difference 4 g between theflexible display 4 and the first and second bodies 1 and 2 is “0” andthe first and second restriction pins 5 b-1 and 5 b-2 are located in thefirst end portions 1 c-2 and 2 c-2 of the first and second restrictionslots 1 c and 2 c. In this state, when the first and second bodies 1 and2 begin to pivot about the first and second hinge shafts 5 a 1 and 5 a-2to fold, the first and second bodies 1 and 2 are guided by the first andsecond restriction pins 5 b-1 and 5 b-2 and the first and secondrestriction slots 1 c and 2 c to gradually move away from the first andsecond hinge shafts 5 a-1 and 5 a-2. When the first and second bodies 1and 2 form an angle of, for example, 90°, therebetween as shown in FIG.10B, the first and second restriction pins 5 b-1 and 5 b-2 are locatedin the middle of the first and second restriction slots 1 c and 2 c andthe first and second bodies 1 and 2 reach a farthest position from thefirst and second hinge shafts 5 a-1 and 5 a-2. When the first and secondbodies 1 and 2 move continuously to be folded, the first and secondbodies 1 and 2 gradually move toward the first and second hinge shafts 5a-1 and 5 a-2. When the first and second bodies 1 and 2 are completelyfolded as shown in FIG. 10C, the first and second restriction pins 5 b-1and 5 b-2 reach the second end portions 1 c-2 and 2 c-2 of the first andsecond restriction slots 1 c and 2 c.

As such, since the first and second bodies 1 and 2 move away from thefirst and second hinge shafts 5 a-1 and 5 a-2 and then move toward thefirst and second hinge shafts 5 a-1 and 5 a-2 during a folding/unfoldingprocess to compensate for the folding/unfolding path difference 4 g, thethird portion 4 c of the flexible display 4 may be bent into a smoothcurved shape. Also, when the foldable device is used in a state whereinthe first and second bodies 1 and 2 form a predetermined unfolding angletherebetween, the third portion 4 c has a smooth curved shape, therebyreducing distortion of a screen.

The first and second restriction slots 1 c and 2 c are not limited tolinear shapes of FIG. 10A, and may have any of various shapes as long asthe folding/unfolding path difference 4 g according to afolding/unfolding structure of the first and second bodies 1 and 2 maybe compensated for.

FIGS. 11A, 11B, and 11C are schematic views of a structure of a hingeshaft 5 a including the first and second bodies 1 and 2 that move to orfrom the first and second hinge shafts 5 a-1 and 5 a-2 according to anexemplary embodiment. FIG. 11A illustrates a state wherein the first andsecond bodies 1 and 2 are unfolded, FIG. 11B illustrates a state whereinthe first and second bodies 1 and 2 are spaced apart by a maximumdistance from the first and second hinge shafts 5 a-1 and 5 a-2, andFIG. 11C illustrates a state wherein the first and second bodies 1 and 2are folded. In FIGS. 11A, 11B, and 11C, the flexible display 4 is notshown. FIG. 11D is a graph showing a movement distance according to afolding angle between the first and second bodies 1 and 2.

Referring to FIG. 11A, the first and second restriction slots 1 c and 2c include first parts 1 c-a and 2 c-a corresponding to afolding/unfolding process from an unfolding state to a state having anangle of, for example, 90°, between the first and second bodies 1 and 2and second parts 1 c-b and 2 c-b corresponding to a folding/unfoldingprocess from the state having the angle of 90° between the first andsecond bodies 1 and 2 and a folding state. The first and second bodies 1and 2 are folded or unfolded by rotating about the first and secondhinge shafts 5 a-1 and 5 a-2. When the first and second bodies 1 and 2are folded, the first and second bodies 1 and 2 form an obtuse angleduring a period when the foldable device moves from the unfolding stateto a state having the receiving start angle of, for example, 90°, andthe first and second support portions 1 b and 2 b are maintained at thesupport position. As a result, the folding/unfolding path difference 4 gmay be sharply increased. When the angle between the first and secondbodies 1 and 2 is less than the receiving start angle, the first andsecond support portions 1 b and 2 b may pivot to the receiving positionat which the receiving space 3 is formed, thereby reducing thefolding/unfolding path difference 4 g to some extent due to thereceiving space 3.

In this regard, the first parts 1 c-a and 2 c-a have profilescorresponding to a sharp change in the folding/unfolding path difference4 g during a folding/unfolding process. When the angle between the firstand second bodies 1 and 2 is less than 90°, since the third portion 4 cof the flexible display 4 is received in the receiving space 3 and thusthe folding/unfolding path difference 4 g is reduced to some extent dueto the receiving space 3, the second parts 1 c-b and 2 c-b do not needto have strict profiles for compensating for the folding/unfolding pathdifference 4 g when compared to the first parts 1 c-a and 2 c-a. Thesecond parts 1 c-b and 2 c-b may just have profiles for moving the firstand second bodies 1 and 2 so that the third portion 4 c of the flexibledisplay 4 smoothly forms the curved portion 4 d and is received in thereceiving space 3.

According to the first and second restriction slots 1 c and 2 c of FIG.11A, a movement distance of the first and second bodies 1 and 2 to orfrom the first and second hinge shafts 5 a-1 and 5 a-2 when the firstand second bodies 1 and 2 fold or unfold is asymmetric about an angle of90° as shown in the graph of FIG. 11D. That is, a change in a movementdistance when the first and second bodies 1 and 2 are guided by thefirst parts 1 c-a and 2 c-a, that is, a gradient of a curve indicatingthe movement distance in FIG. 11D, is sharply increased, and a movementdistance when the first and second bodies 1 and 2 are guided by thesecond parts 1 c-b and 2 c-b is relatively moderately changed.

When the first and second bodies 1 and 2 are completely unfolded asshown in FIG. 11A, the folding/unfolding path difference 4 g between theflexible display 4 and the first and second bodies 1 and 2 is “0” andthe first and second restriction pins 5 b-1 and 5 b-2 are located in thefirst end portions 1 c-2 and 2 c-1 of the first and second restrictionslots 1 c and 2 c. In this state, when the first and second bodies 1 and2 begin to pivot about the first and second hinge shafts 5 a 1 and 5 a-2to fold, due to operations of the first and second restriction pins 5b-1 and 5 b-2 and the first parts 1 c-a and 2 c-a, the first and secondbodies 1 and 2 rapidly move away from the first and second hinge shafts5 a-1 and 5 a-2. When the first and second bodies 1 and 2 form an angleof 90° therebetween as shown in FIG. 11B, the first and secondrestriction pins 5 b-1 and 5 b-2 are located in the middle of the firstand second restriction slots 1 c and 2 c, that is, a boundary betweenthe first parts 1 c-a and 2 c-a and the second parts 1 c-b and 2 c-b,and the first and second bodies 1 and 2 reach a farthest position fromthe first and second hinge shafts 5 a-1 and 5 a-2. When the first andsecond bodies 1 and 2 move continuously to folded, the first and secondrestriction pins 5 b-1 and 5 b-2 are guided by the second parts 1 c-band 2 c-b, and the first and second bodies 1 and 2 gradually move towardthe first and second hinge shafts 5 a-1 and 5 a-2. When the first andsecond bodies 1 and 2 are completely folded as shown in FIG. 11C, thefirst and second restriction pins 5 b-1 and 5 b-2 reach the second endportions 1 c-2 and 2 c-2 of the first and second restriction slots 1 cand 2 c.

In other exemplary embodiments, the first and second restriction slots 1c and 2 c may have any of various shapes for compensating for thefolding/unfolding path difference 4 g between the flexible display 4 andthe first and second bodies 1 and 2 according to a folding/unfoldingangle.

FIG. 12A is an exploded perspective view illustrating a connectionrelationship between the first restriction pin 5 b-1 and the firstrestriction slot 1 c according to an exemplary embodiment. FIG. 12B is across-sectional view taken along line E-E′ of FIG. 12A. The pathdifference compensating unit will now be explained with reference toFIGS. 8, 12A, and 12B.

Referring to FIGS. 8, 12A, and 12B, first and second pin members 5 d-1and 5 d-2 are illustrated. The first and second restriction pins 5 b-1and 5 b-2 are respectively provided on the first and second pin members5 d-1 and 5 d-2. The first and second pin members 5 d-1 and 5 d-2 areprovided on the fixed hinge 5-3. For example, the first and second pinmembers 5 d-1 and 5 d-2 are inserted into slot holes 5 c-4 of thelocking member 5 c and are respectively fixed to the first and secondhinge shafts 5 a-1 and 5 a-2 due to a fastening member 5 e. Accordingly,the first and second restriction pins 5 b-1 and 5 b-2 may have fixedpositions with respect to the first and second hinge shafts 5 a-1 and 5a-2.

The first restriction slot 1 c including the first part 1 c-a and thesecond part 1 c-b shown in FIG. 11A is formed in an end portion of thefirst movable frame 52-1 that is close to the first hinge shaft 5 a-1.The first restriction pin 5 b-1 is inserted into the first restrictionslot 1 c. As marked by brackets in FIGS. 12A and 12B, the secondrestriction slot 2 c including the first part 2 c-a and the second part2 c-b shown in FIG. 11A is also formed in the second movable frame 52-2.The second restriction pin 5 b-2 is inserted into the second restrictionslot 2 c.

The path difference compensating unit according to an exemplaryembodiment may be realized by using the above configuration. Shapes ofthe first and second restriction slots 1 c and 2 c are not limited tothose in the above, and may be determined to compensate for thefolding/unfolding path difference 4 g in consideration of thefolding/unfolding path difference 4 g during a folding/unfolding processof the first and second bodies 1 and 2.

The first and second support portions 1 b and 2 b may move between thesupport position and the receiving position as described above. Thefirst and second support portions 1 b and 2 b are located at the supportposition when the first and second bodies 1 and 2 are located at theunfolding position, and move to the receiving position when the firstand second bodies 1 and 2 are located at the folding position. In orderfor the first and second bodies 1 and 2 to be used at the inclinedposition between the unfolding position and the folding position, thefirst and second support portions 1 b and 2 b may be located at thesupport position when the first and second bodies 1 and 2 are in aposition from the unfolding position to the inclined position, and maymove to the receiving position when the first and second bodies 1 and 2fold beyond the inclined position. Accordingly, the receiving startangle may be equal to or greater than an angle corresponding to theinclined position. Since the foldable device is rarely used at anopening angle that is less than 90°, the first and second supportportions 1 b and 2 b may be maintained at the support position at theopening angle ranging from 180° to 90°.

The foldable device may include a restriction unit that maintains thefirst and second support portions 1 b and 2 b at the support positionwhen the first and second bodies 1 and 2 are in a position from theunfolding position to the receiving start position corresponding to thereceiving start angle, and allows the first and second support portions1 b and 2 b to move to the receiving position when the first and secondbodies 1 and 2 folds beyond the receiving start position.

FIG. 13 is a schematic view of the restriction unit according to anexemplary embodiment. Although only a mechanism that restricts themovement of the first support portion 1 b is shown in FIG. 13, the samemechanism applies to a structure that restricts the movement of thesecond support portion 2b. Hence, reference numerals without parenthesesin FIG. 13 denotes an element of the structure that restricts themovement of the first support portion 1 b, and reference numerals inparentheses denotes an element of the structure that restricts themovement of the second support portion 2 b.

Referring to FIG. 13, first and second support arms 56-1 and 56-2 thatrespectively support the first and second support portions 1 b and 2 bare illustrated. The first and second support arms 56-1 and 56-2 mayrespectively pivot about fixed positions with respect to the first andsecond hinge shafts 5 a-1 and 5 a-2. For example, the first and secondsupport arms 56-1 and 56-2 may be pivotably supported on the fixed hinge5-3.

FIG. 14 is an exploded perspective view of a structure in which thefirst and second support arms 56-1 and 56-2 are pivotably supportedaccording to an exemplary embodiment. Referring to FIGS. 8 and 14, firstand second pivot pins 56-1 a and 56-2 a are respectively provided on endportions of the first and second support arms 56-1 and 56-2, and arerespectively pivotably inserted into first and second pivot holes 5 c-4a and 5 c-4 b that are formed in the locking member 5 c.

First and second guide pins 56-1 b and 56-2 b are respectively providedon the first and second support arms 56-1 and 56-2. The first and secondguide pins 56-1 b and 56-2 b are respectively inserted into first andsecond guide slots 57-1 and 57-2. Although the first and second guidepins 56-1 b and 56-2 b pass through the first and second guide slots57-1 and 57-2, extend under the first and second support portions 1 band 2 b, and support the first and second support portions 1 b and 2 bin the present exemplary embodiment, for convenience of explanation,FIG. 13 illustrates that support protrusions 56-1 c and 56-2 c thatsupport the first and second support portions 1 b and 2 b arerespectively provided on the first and second support arms 56-1 and56-2.

The first and second guide slots 57-1 and 57-2 are respectively formedin the first and second hinge frames 51-1 and 51-2. The first and secondguide slots 57-1 and 57-2 include support parts 57-1 a and 57-2 a andreceiving parts 57-1 b and 57-2 b. The support parts 57-1 a and 57-2 acorrespond to a period from the unfolding position to the receivingstart position, and the receiving parts 57-1 b and 57-2 b correspond toa period from the receiving start position to the folding position. Thesupport parts 57-1 a and 57-2 a are formed so that the first and secondsupport arms 56-1 and 56-2 are maintained at a position at which thefirst and second support arms 56-1 and 56-2 support the first and secondsupport portions 1 b and 2 b while the first and second bodies 1 and 2pivot from the unfolding position to the receiving start position. Thereceiving parts 57-1 b and 57-2 b are formed so that the first andsecond support arms 56-1 and 56-2 are allowed to pivot away from thefirst and second support portions 1 b and 2 b and thus the first andsecond support portions 1 b and 2 b are allowed to pivot to thereceiving position while the first and second bodies 1 and 2 pivot fromthe receiving start position to the folding position. Although the firstand second support portions 1 b and 2 b pivot due to their weights fromthe support position to the receiving position in the present exemplaryembodiment, an elastic member that applies an elastic force in adirection in which the first and second support portions 1 b and 2 bpivot to the receiving position may be provided, and thus the first andsecond support portions 1 b and 2 b may pivot from the support positionto the receiving position due to the elastic force of the elasticmember.

FIG. 13 illustrates a state (a) wherein the first and second bodies 1and 2 are located at the unfolding position. The first and second guidepins 56-1 b and 562 b are located in the support parts 57-1 a and 57-2a, and the first and second support portions 1 b and 2 b are supportedby the first and second support arms 56-1 and 56-2 and are maintained atthe support position. Accordingly, the flexible display 4 is supportedby the first and second fixed portions 1 a and 2 a, the first and secondsupport portions 1 b and 2 b, and a movable guide member 7 which will beexplained below and is maintained flat.

In the state (a) of FIG. 13, when the first and second bodies 1 and 2begin to fold, the first and second bodies 1 and 2 move away from thefirst and second hinge shafts 5 a-1 and 5 a-2 due to the path differencecompensating unit. Until the first and second bodies 1 and 2 reach thereceiving start position as in a state (b) of FIG. 13, since the firstand second guide pins 56-1 b and 56-2 b are guided by the support parts57-la and 57-2a, the first and second support arms 56-1 and 56-2 aremaintained at a position at which the first and second support arms 56-1and 56-2 support the first and second support portions 1 b and 2 b.

When the first and second bodies 1 and 2 fold beyond the receiving startposition, the first and second guide pins 56-1 b and 56-2 b are guidedby the receiving parts 57-1 b and 57-2 b. The first and second supportarms 56-1 and 56-2 pivot about the first and second pivot pins 56-1 aand 56-2 a away from the first and second support portions 1 b and 2 b.The first and second support portions 1 b and 2 b pivot away from a rearsurface of the flexible display 4, and the receiving space 3 (see FIG.3) begins to be formed in the first and second bodies 1 and 2. The firstand second bodies 1 and 2 slide toward the first and second hinge shafts5 a-1 and 5 a-2 due to the path difference compensating unit, and thethird portion 4 c of the flexible display 4 is moderately bent and isreceived in the receiving space 3.

When the first and second bodies 1 and 2 reach the folding position asin a state (c) of FIG. 13, the first and second support portions 1 b and2 b reach the receiving position, and the receiving space 3 is formed inthe first and second bodies 1 and 2 as shown in FIG. 3. The thirdportion 4 c of the flexible display 4 forms the curved portion 4 d andis received in the receiving space 3.

The first and second guide slots 57-1 and 57-2 are not limited to shapesin FIG. 13. Shapes of the first and second guide slots 57-1 and 57-2 mayvary according to positions of the first and second pivot holes 5 c-4 aand 5 c-4 b relative to the first and second hinge shafts 5 a-1 and 5a-2.

A structure of the restriction unit is not limited to that in FIGS. 13and 14. The restriction unit according to an exemplary embodiment isshown in FIG. 15. The restriction unit of the present exemplaryembodiment includes two link arms. Although only a mechanism thatrestricts the movement of the first support portion 1 b is shown in FIG.15, the same mechanism applies to a structure that restricts themovement of the second support portion 2 b.

Referring to FIG. 15, first and second link arms 61 and 62 areillustrated. The first link arm 61 may pivot about a fixed position withrespect to the first hinge shaft 5 a-1. For example, the first link arm61 may be pivotably supported on the fixed hinge 5-3. For example, apivot pin 61a that is provided on one end portion of the first link arm61 may be pivotably inserted into the first pivot hole 5 c-4 a of FIG.14. One end portion of the second link arm 62 and the other end portionof the first link arm 61 are pivotably connected to each other by aguide pin 63. The other end portion of the second link arm 62 ispivotably connected to the first support portion lb. The guide pin 63 isguided by a guide slot 64. The guide slot 64 may be formed in, forexample, the first hinge frame 51-1. The guide slot 64 includes asupport part 64 a and a receiving part 64 b. The support part 64 aaccommodates the guide pin 63 during a period when the foldable devicemoves from the unfolding position to the receiving start position. Thereceiving part 64 b accommodates the guide pin 63 during a period whenthe foldable device moves from the receiving start position to thefolding position.

In this configuration, the first and second link arms 61 and 62 and thefirst support portion 1 b constitute a three-link (3-link) structure. Inother words, in FIG. 13, the first and second support arms 56-1 and 56-2respectively include the first and second link arms 61 and 62, and thefirst and second guide pins 56-1 b and 56-2 b pivotably connect thefirst and second link arms 61 and 62. The guide slot 64 is amodification of the first and second guide slots 57-1 and 57-2 of FIG.13 in order to suit the 3-link structure.

FIG. 15 illustrates a state (a) wherein the first and second bodies 1and 2 are located at the unfolding position. The guide pin 63 is locatedin the support part 64 a and the first support portion 1 b is maintainedat the support position. In the state (a) of FIG. 15, when the first andsecond bodies 1 and 2 begin to fold, the first body 1 moves away fromthe first hinge shaft 5 a-1 due to the path difference compensatingunit. Until the first body 1 reaches the receiving start position as ina state (b) of FIG. 15, since the guide pin 63 is guided by the supportpart 64 a, the first support portion 1 b is maintained at the supportposition.

When the first and second bodies 1 and 2 fold beyond the receiving startposition, the guide pin 63 is guided by the receiving part 64 b. Thefirst and second link arms 61 and 62 pull the first support portion 1 btoward the receiving position, and thus the first support portion 1 bpivots away from the rear surface of the flexible display 4 and thereceiving space 3 (see FIG. 3) begins to be formed in the first andsecond bodies 1 and 2. The first body 1 slides toward the first hingeshaft 5 a-1 due to the path difference compensating unit, and the thirdportion 4 c of the flexible display 4 is moderately bent and is receivedin the receiving space 3.

When the first and second bodies 1 and 2 reach the folding position asshown in a state (c) of FIG. 15, the first support portions 1 b and 2 breach the receiving position and the receiving space 3 is formed in thefirst and second bodies 1 and 2 as shown in FIG. 3. The third portion 4c of the flexible display 4 forms the curved portion 4 d and is receivedin the receiving space 3.

FIGS. 16A, 16B, and 16C are schematic views of the restriction unitaccording to another exemplary embodiment. Although a mechanism thatmoves the first support portion 1 b between the support position and areceiving position is illustrated in FIGS. 16A, 16B, and 16C, the samemechanism applies to a structure that moves the second support portion 2b between the support position and the receiving position.

Referring to FIGS. 16A, 16B, and 16C, a connection member 5 j isillustrated. The connection member 5 j may be, for example, a wire. Oneend portion 5 j-1 of the connection member 5 j may be fixed to a fixedposition with respect to the first hinge shaft 5 a-1. The other endportion 5 j-2 of the connection member 5 j is connected to a rack gear 5g. The rack gear 5 g may be slidably provided on, for example, the firsthinge frame 51-1.

For example, the one end portion 5 j-1 of the connection member 5 j maybe connected to the fixed hinge 5-3. A pulley 5 f-1 is provided on thefirst hinge shaft 5 a-1. The connection member 5 j is in contact withthe pulley 5 f-1 and is wound around the pulley 5 f-1 during afolding/unfolding process of the first and second bodies 1 and 2. Whenthe connection member 5 j is wound around the pulley 5 f-1, a distancebetween a contact point between the connection member 5 and the pulley 5f-1 and the other end portion 5 j-2 of the connection member 5 ischanged, and the rack gear 5 g slides.

When the one end portion 5 j-1 of the connection member 5 j is connectedto the second hinge frame 51-2 and a pulley 5 f-2 is provided on thesecond hinge shaft 5 a-2, a sliding amount of the rack gear 5 g may beincreased by causing the connection member 5 j to be wound around thepulleys 5 f-1 and 5 f-2 during a folding/unfolding process.

When the first and second bodies 1 and 2 unfold, a return spring 5 kapplies an elastic force to the rack gear 5 g so that the rack gear 5 gmoves away from the first hinge shaft 5 a-1.

The first support portion 1 b is supported by a rotating cam 5 h. Apinion gear 5 h-1 that is engaged with the rack gear 5 g is provided onthe rotating cam 5 h. Accordingly, as the rack gear 5 g slides, therotating cam 5 h rotates. The rotating cam 5 h includes a first cam path5 h-2 that has a constant distance from the center of rotation and asecond cam path 5 h-3 that has a reduced distance from the center ofrotation. While the first support portion 1 b is supported by the firstcam path 5 h-2, the first support portion 1 b is maintained at thesupport position. When contact between the first support portion 1 b andthe first cam path 5 h-2 ends, the first support portion 1 b issupported by the second cam path 5 h-3 and pivots to the receivingposition.

FIG. 16A illustrates a state wherein the first and second bodies 1 and 2are located at the unfolding position. The first support portion 1 b issupported by the first cam path 5 h-2 and is maintained at the supportposition.

In the state of FIG. 16A, when the first and second bodies 1 and 2 beginto fold, the connection member 5 j begins to be wound around the firstand second pulleys 5 f-1 and 5 f-2. Accordingly, the rack gear 5 slidestoward the first hinge shaft 5 a-1, and the rotating cam 5 h rotates.Until the first and second bodies 1 and 2 reach the receiving startposition as shown in FIG. 16B, since the first support portion 1 b isguided by the first cam path 5 h-2, the first support portion 1 b ismaintained at the support position.

When the first and second bodies 1 and 2 fold beyond the receiving startposition, contact between the first cam path 5 h-2 and the first supportportion 1 b ends and the first support portion 1 b is supported by thesecond cam path 5 h-3. Accordingly, the first support portion 1 b pivotsaway from the rear surface of the flexible display 4 and the receivingspace 3 (see FIG. 3) begins to be formed in the first and second bodies1 and 2. The third portion 4 c of the flexible display 4 is moderatelybent and begins to be received in the receiving space 3.

When the first and second bodies 1 and 2 reach the folding position asshown in FIG. 16C, the first support portion 1 b reaches the receivingposition and the receiving space 3 is formed in the first and secondbodies 1 and 2 as shown in FIG. 3. The third portion 4 c of the flexibledisplay 4 forms the curved portion 4 d and is received in the receivingspace 3.

The return spring 5 k is connected to the rack gear 5 g and applies atensile force to the connection member 5 j having a wire shape.Accordingly, when the first and second bodies 1 and 2 unfold, due to anelastic force of the return spring 5, the rack gear 5 g slides in adirection that is opposite to a direction in which the rack gear 5 gslides when the first and second bodies 1 and 2 fold, and the rotatingcam 5 h also rotates in an opposite direction. Accordingly, the firstsupport portion 1 b returns from the receiving position to the supportposition.

Assuming that a strip having bending elasticity is used as theconnection member 5 j, when the first and second bodies 1 and 2 unfold,the strip is spread due to elasticity and pushes the rack gear 5 g in adirection that is opposite to a direction in which the rack gear 5 gslides when the first and second bodies 1 and 2 fold. Accordingly, thereturn spring 5 k may be omitted.

Referring back to FIG. 6, a cover member 8 surrounds an area between thefirst and second hinge units 5-1 and 5-2 so that a receiving space inthe foldable device is prevented from being exposed to the outside. Forexample, the cover member 8 may include an extending portion 81 thatextends along facing edges of the first and second hinge units 5-1 and5-2 and side wall portions 82 that are located on both end portions ofthe extending portion 81. The cover member 8 is coupled to the hingeunit 5 by slightly opening outward the side wall portions 82 to surroundthe first and second gear portions 51-1 b and 51-2 b.

Referring back to FIGS. 6 and 7, the movable support member 7 includinga support surface 71 on which the third portion 4 c of the flexibledisplay 4 is supported is illustrated. The movable support member 7 islocated at a first position at which the movable support member 7supports the third portion 4 c of the flexible display 4 when the firstand second bodies 1 and 2 are located at the unfolding position. Themovable support member 7 supports the third portion 4 c of the flexibledisplay 4 between the first and second support portions 1 b and 2 b.When the first and second bodies 1 and 2 change to the folding position,the movable support member 7 is spaced apart from the third portion 4 cof the flexible display 4 and is located at a second position at whichthe receiving space 3 for receiving the curved portion 4 d is formed.That is, the movable support member 7 moves between the first positionand the second position as the first and second bodies 1 and 2 changebetween the unfolding position and the folding position. As such, whenthe first and second bodies 1 and 2 are located at the unfoldingposition, the third portion 4 c of the flexible display 4 may besupported by the movable support member 7 to be spread flat. As thefoldable device changes from the folding position to the unfoldingposition and the movable support member 7 is raised from the secondposition to the first position, the movable support member 7 mayadjacently support the third portion 4 c of the flexible display 4.Accordingly, even when the foldable device is used at the inclinedposition having a predetermined angle, the movable support member 7 maystably support the third portion 4 c of the flexible display 4 alongwith the first and second support portions 1 b and 2 b, thereby reducingdistortion of a screen at the third portion 4 c.

FIG. 17 is an exploded perspective view of a structure that moves themovable support member 7 between the first position and the secondposition according to an exemplary embodiment. Referring to FIG. 17,slots 72 that extend in a folding/unfolding direction of the first andsecond bodies 1 and 2, that is, the longitudinal direction L, are formedin the movable support member 7. One pair of guide portions 73-1 and73-2 that are inserted into the slots 72 are provided around facingedges of the first and second hinge units 5-1 and 5-2. For example, theguide portions 73-1 and 73-2 may be provided on upper ends of ribs 74-1and 74-2 that respectively upwardly extend from the first and secondhinge frames 51-1 and 51-2. Insertion grooves 75 are formed in themovable support member 7, and the guide portions 73-1 and 73-2 areinserted into the slots 72 through the insertion grooves 75. Theinsertion grooves 75 are formed at central portions of the slots 72 in alongitudinal direction 72L of the slots 72. While the first and secondbodies 1 and 2 fold or unfold, the guide portions 73-1 and 73-1 move inthe longitudinal direction 72L of the slots 72 and a movement path ofthe guide portions 73-1 and 73-2 does not overlap the insertion grooves75. Accordingly, while the guide portions 73-1 and 73-2 are insertedinto the slots 72 and then the movable support member 7 is raised andlowered, the guide portions 73-1 and 73-2 are not separated from theslots 72 through the insertion grooves 75.

FIGS. 18A and 18B are cross-sectional views taken along line F-F′ ofFIG. 17, respectively illustrating a state wherein the movable supportmember 7 is located at the second position and a state wherein themovable support member 7 is located at the first position. Referring toFIG. 18A, the first and second bodies 1 and 2 are located at the foldingposition. The guide portions 73-1 and 73-2 are located at a farthestposition from each other, and the movable support member 7 is located atthe second position. The curved portion 4 d of the flexible display 4 isreceived in the receiving space 3 that is formed due to the first andsecond support portions 1 b and 2 b and the movable support member 7.

When the first and second bodies 1 and 2 unfold in the state of FIG.18A, the guide portions 73-1 and 73-2 slide in the slots 72 to movetoward each other, and the movable support member 7 is raised toward theflexible display 4 and continuously adjacently supports the thirdportion 4 c of the flexible display 4. Accordingly, even when thefoldable device is used at the inclined position, the third portion 4 cof the flexible display 4 may be stably supported by the first andsecond fixed portions 1 a and 2 a, the first and second support portions1 b and 2 b, and the support surface 71 of the movable support member 7.

When the first and second bodies 1 and 2 are completely unfolded asshown in FIG. 18B, the movable support member 7 is located at the firstposition and the third portion 4 c of the flexible display 4 is stablysupported by the support surface 71.

The guide portions 73-1 and 73-2 and the slots 72 may be provided at twoor more places in the width direction W of the foldable device in orderfor the movable support member 7 not to be inclined when being raisedand lowered between the first and second positions.

The movement of the guide portions 73-1 and 73-2 in a width direction72W of the slots 72 is restricted and the movement of the guide portions73-1 and 73-2 in the longitudinal direction 72L of the slots 72 isallowed. That is, the vertical movement of the movable support member 7is restricted by the guide portions 73-1 and 73-2. Accordingly, themovable support member 7 may be stably vertically raised and loweredwithout being shaken. Also, even when the first and second bodies 1 and2 are located at the unfolding position, the support surface 71 of themovable support member 7 may not be inclined and may stably support flatthe third portion 4 c of the flexible display 4.

Hereinafter, the structure of a foldable device 20 according to anotherexemplary embodiment will be described in great detail.

FIG. 19 is a perspective view indicating an unfolding state of thefoldable device 20 according to another exemplary embodiment. FIG. 20 isa side sectional view which schematically illustrates a relation betweenthe flexible display and a fixed portion of the body in the foldabledevice 20, and FIG. 21 is a side sectional view which schematicallyindicates a state of folding of the foldable device 20 of FIG. 20.

Referring to FIGS. 19-21, the foldable device 20 according to anotherexemplary embodiment may include a first body 210, a second body 220,and a flexible display 240.

The first body 210 and the second body 220 are interconnected andintegrated into one body, an as illustrated in FIGS. 19 and 20. Thefirst body 210 and the second body 220 may be unfolded or folded asillustrated in FIG. 21. The first body 210 and the second body 220 mayhave a rectangular shape and an upper surface of the first body 210 andthe second body 220 may fix or support the flexible display 240. Insidethe first body and the second body 210, 220, a printed circuit boardwhere various electronic parts are mounted can be installed to realizethe functions of the foldable device 20.

The flexible display 240 may include a flexible display panel whichdisplays an image and a transparent protection sheet which is installedon a front surface of the flexible display panel. For example, theflexible display panel may use an Organic Light Emitting Diode (OLED)panel. In addition, the flexible display 240 may further include a touchpanel as an input means. For example, a touch panel can be disposedbetween a transparent protection sheet and a flexible display panel. Inaddition, the flexible display 240 may further include various opticalpanels or films.

A part of the flexible display 240 is fixed to the first body 210, andanother part is fixed to the second body 220. Therefore, the flexibledisplay 240 may be divided into the first portion 241 which is fixed tothe first body 210, the second portion 242 fixed to the second body 220,and a third portion 243 between the first body 210 and the second body220.

The first body 210 includes a first fixing portion 211 where the firstportion 241 of the flexible display is fixed, and a second fixingportion 221 where the second portion 242 is fixed. The first portion 241and the second portion 242 of the flexible display 240 are fixed to thefirst fixing portion 211 and the second fixing portion 221,respectively, by fixing members such as adhesive, both-sided tape. Thefirst fixing portion 211 of the first body 210 constitutes the firstsupport portion which supports the first portion 241 of the flexibledisplay 240, and the second fixing portion 221 of the second body 220constitutes the second support portion which supports the second portion242 of the flexible display 240.

The third portion 243 of the flexible display 240 may be changedaccording to a relative position of the first body 210 and the secondbody 220. For example, the third portion 243 may not to be fixed to thefirst body 210 or the second body 220. As another example, a part of thethird portion 243 of the flexible display 240 may be fixed to a part ofthe first body 210 and the second body 220. The third portion 243 issupported by the third supporting unit of the flexible display 240.

As illustrated in FIG. 21, when the first body 210 and the second body220 are in a folded state, the third portion 243 of the flexible display240 forms the curved portion 244 having a predetermined curvature.Therefore, when the first body 210 and the second body 220 are folded,the third portion 243 of the flexible display 240 is not folded to beangular, and the third portion 243 forms the curved portion 244 that hasa curved shape.

In the folded state, the curved third portion 243 of the flexibledisplay 240 is accommodated in the foldable device 20, and a receivingspace 230 is provided inside the first body 210 and the second body 220.To be specific, while the foldable device 20 is folded, the firstportion 241 and the second portion 242 of the flexible display 240 arelocated to be adjacent to each other or in contact with each other, andthe third portion 243 is bent toward inside the first body 210 and thesecond body 220 and is accommodated in the receiving space 230 in adroplet shape.

A hinge unit 250 is provided between the first body 210 and the secondbody 220, and the first body 210 and the second body 220 are connectedpivotably to the hinge unit 250. Therefore, the first body 210 and thesecond body 220 may be changed to a folding position that the first body210 and the second body 220 are in contact with each other centering onthe hinge unit 250, and an unfolding position that the first body 210and the second body 220 are spaced apart from each other to form oneplane. In other words, the hinge unit 250 allows the first supportportion 211 and the second support portion 221 to pivot around a thirdsupport portion including the first and second support wings 121 and222, to change the state of the flexible display 240 from an open stateto a closed state or from the closed state to the open state.

As an example, the hinge unit 250 may include two hinge axes 251 and 252which are spaced apart from each other in a length direction (Xdirection). The first and second bodies 210 and 220 may rotate withrespect to the first and second hinge axes 251 and 252 and may change toan unfolding position and a folding position.

The flexible display 240 may not be folded with angles due to itscharacteristics, and when the flexible display 240 is folded, a curvedportion 244 having predetermined curvature is formed on a folded part.The foldable device 20 using the flexible display 240, when the firstand second bodies 210, 220 are folded from unfolded state or vice versa,may have a phase difference between the flexible display 240 and thefirst and second bodies 210 and 220. Here, the phase differenceindicates that length of the flexible display 240 in a folded state isshorter than length of the first and second bodies 210, 220 in a foldedstate. Such phase difference occurs as the flexible display 240 may notbe folded with angles.

In order to compensate such phase difference, the foldable device 20 mayinclude a phase difference compensation unit. The phase differencecompensation unit may move at least one of the first and second bodies210 and 220 in a direction away from the hinge axis 251 or 252 when thestate of the at least one of the first and second bodies 210 and 220changes from the unfolded state to another position, and may move atleast one of the first and second bodies 210 and 220 in a directioncloser to the hinge axis 251 or 252.

The foldable device 20 may be a portable mobile device such as acommunication terminal, a game device, a multimedia device, a portablecomputer, and a photographing device. In addition, the foldable device20 may implemented with any device including the first body 210 in whichthe first portion 241 of the flexible display 240 is fixed, and thesecond body 220 in which the second portion 242 of the flexible display240 is fixed, so that the flexible device 340 is foldable with respectto the first body 210.

The first and second bodies 210, 220 may include a processing unit toperform functions according to a use of the foldable device 20,input/output means, and power unit. When the foldable device 20 is amultimedia terminal from which a user may appreciate a video and music,the processing unit may include an image information processor and asound information processor. When the foldable device 20 is acommunication terminal, the processing unit may include a communicationmodule. The input/output means may include a video inputter/outputter, asound inputter/outputter, and a manipulator for user manipulation. Themanipulator may be realized by a touch panel integrated to the flexibledisplay 240.

The first and second bodies 210 and 220 of the foldable device 20 may bepositioned in a folded state as illustrated in FIG. 21. In particular,the third portion 243 of the flexible display 240 may form a curvedportion 244 in a droplet shape. However, if movement of a third portion243 of the flexible display 240 which is supported by the first andsecond support wings 212 and 222 is not restricted while the first body210 and the second body 220 are being folded, a part of the thirdportion 243 which is connected to the first portion 241 and the secondportion 242 of the flexible display 240 is not smoothly bent accordingto the first and second support wings 212 and 222 as illustrated in FIG.21, but as in FIG. 22, it may be disposed apart from the first andsecond support wings 212, 222, protrude upward, and may be distorted ina wave shape. If such phenomenon occurs due to the distorted part 25,life of the flexible display 240 may decrease. Here, FIG. 22 is a viewto explain a phenomenon that, when movement of the flexible display 240supported by the first support wing 212 is not additionally controlled,the part 25 of the flexible display is distorted. Though not illustratedin FIG .22, the part 25 of the third portion 243 of the flexible display240 supported by the second support wing 222 is distorted in the samemanner as in FIG. 22.

Therefore, in order to overcome the above problem, when the first body210 and the second body 220 are folded, there may be a displayrestriction member to restrict operations of the flexible display 240.

FIG. 23 is an exploded perspective view indicating a flexible displayfrom a foldable device according to another exemplary embodiment. FIG.24 is an exploded perspective view indicating a state where a supportportion is divided from the foldable device, and FIG. 23 is an explodedperspective view of a hinge unit used for the foldable device of FIG.23. The hinge unit is symmetrical in left and right directions in awidth direction (Y direction) of the foldable device, and FIG. 23illustrates the hinge unit of one side. FIG. 26 is an explodedperspective view indicating a relation between the hinge unit and thesupport wings in the foldable device according to another exemplaryembodiment.

Referring to FIGS. 23-26, the foldable device 20 according to antherexemplary embodiment includes the first body 210, the second body 220,the hinge unit 230, and the flexible display 240.

The first body 210 includes a first upper case 210-1 and a first lowercase 210-2. The first upper case 210-1 includes the first fixed portion211 and the first support wings 212. To the first fixed portion 211, thefirst portion 241 of the flexible display 240 is fixed. In the firstfixed portion 211, a stopper 213 which restricts rotation of the firstsupport wing 212 may be installed at a lower part of the first supportwing 212. In the present exemplary embodiment, the stopper 213 has atriangular prism shape.

The first support wing 212 is installed at one side of the first fixedportion 211 to be parallel with the first fixed portion 211, and rotatesat a predetermined angle with respect to the first fixed portion 211.The first support wing 212 is formed to be a rectangular shape plate,and at a lower part of one side which is adjacent to the first fixedportion 211, a pair of rotation axis 214 is provided. In addition, thepair of rotation axis 214, as illustrated in FIG. 27, protrudes at bothsides in a width direction of the first support wing 212 as illustratedin FIG. 27. The first support wing 212 constitutes the third supportpart which supports the third portion 243 of the flexible display 240.

At an upper surface of the first support wing 212, a part of the thirdportion 243 of the flexible display 240 is attached by a fixing member216 and is fixed. As the fixing member 216, both-sided tape and anadhesive may be used. An area (hereinafter, a first connection part 243a) which is connected to the first portion 241 from among the thirdportion 243 of the flexible display 240 is not fixed to the firstsupport wing 212 and is placed apart from it. In addition, an area 243 bsupported by the first support wing 212 from among the third portion 243of the flexible display 240 is fixed to an upper surface of the firstsupport wing 212. Accordingly, when the first support wing 212 rotates,the third portion 243 of the flexible display 240 may rotate with thefirst support wing 212 in an integrated manner.

FIG. 27 is an exploded rear perspective view indicating the firstsupport wing 212 separated from the first body 210 of the foldabledevice 20 according to another exemplary embodiment.

Referring to FIG. 27, at an inner wall 210 a of the first upper case210-1 of the first body 210, a slot hole 215 where the rotation axis 214of the first support wing 212 is inserted is provided at a placeadjacent to the first fixing part 211. In the first upper case 210-1,there is a pair of slot holes 215 that corresponds to a pair of rotationaxis 214 of the first support wing 212. The slot hole 215 is in a linearshape and has a length which is bigger than a radius of the rotationaxis 214. Therefore, when the first support wing 212 is inclineddownward in a horizontal state, the first support wing 212 may move asmuch as the difference between the length of the slot hole 215 and thediameter of the rotation axis 214 with respect to the first body 210 andthus, by phase difference between the first support wing 212 and theflexible display 240, stress applied to the flexible display 240 may beabsorbed.

The first lower case 210-2 is combined with the first upper case 210-1and constitutes the first body 210. When space is formed between thefirst lower case 210-2 and the first upper case 210-1, there may be aprinted circuit board to embody a processing unit, input/output means,communication means, and a power unit so that the foldable device 20 mayperform a function according to uses.

As shown in FIG. 24, the second body 220 includes the second upper case220-1 and the second lower case 220-2. The second upper case 220-1includes the second fixed portion 221 and the second support wing 222.The structure of the second fixed portion 221 and the second supportwing 222 of the body 220 is the same as the first fixed portion 211 andthe first support wing 212 and thus, the detailed explanation will beomitted. Therefore, in the second upper case 220-1 of the second body220, a pair of slot holes 225 is provided to which a pair of rotationaxis 224 of the second support wing 222 is inserted. The second supportwing 222 constitutes the third support portion which supports the thirdportion 243 of the flexible display 240. Therefore, the third supportportion may be composed of the first support wing 212 and the secondsupport wing 222.

At an upper surface of the second support wing 222, a part of the thirdportion 243 of the flexible display 240 is fixed by a fixing member andis attached. As the fixing member, a both-sided tape and an adhesive maybe used. At this time, from among the third portion 243 of the flexibledisplay 240, a part of an area (hereinafter, the second connection part)which is connected to the second portion 242 is not fixed to the secondsupport wing 222, but is separated. In addition, from among the thirdportion 243 of the flexible display 240, a part 243 d which is supportedby the second support wing 222 is fixed to an upper surface of thesecond support wing 222. Therefore, when the second wing 222 rotates,the third portion of the flexible display 240 may be rotated in anintegrated manner with the second wing 222. A central part 243 c of thethird portion 243 of the flexible display 240 is not fixed to the firstand second support wings 212, 222 and is spaced apart from it. Thecentral part 243 c of the third portion 243 of the flexible display 240may be supported by a central support member to be described later.Therefore, the third support part which supports the third portion 243of the flexible display 240 may include the first support wing 212, thesecond support wing 222, and the central support member.

The hinge unit 250 is installed between the first body 210 and thesecond body 220, and may convert from an unfolded state of the firstbody 210 and the second body 220 to a folded state, or from the foldedstate to the unfolded state. In addition, the hinge unit 250, when thefirst body 210 and the second body 220 rotate between an unfoldingposition and a folding position, is formed so that the first supportwing 212 and the second support wing 222 are operable in associationwith each other. That is, when the flexible display 240 installed on abody is changed from an open state to a closed state by the hinge unit250, or from the closed state to the open state, the first support wing212 of the third support part rotates with respect to the first supportpart 211, and the second support wing 222 of the third support partrotates with respect to the second support part 221. The third supportpart rotating with respect to the first support part and second supportparts 211, 221 may be seen as the first and second support parts 211,221 rotating with respect to the third support part.

Referring to FIGS. 24, 25, and 26, the hinge unit 250 may include afixing hinge 260, first and second hinge frames 270 and 280, a lockingmember 290, an interlocking bar 2100, first and second support arms 2110and 2120, first and second moving members 2130 and 2140.

The fixing hinge 260 includes the first hinge axis 251 and the secondhinge axis 252 which are arranged in parallel to each other. The firstand second hinge axes 251 and 252 become rotation standard in a casewhere the first and second bodies 210, 220 are changed from an unfoldedstate to a folded state or in a reverse case. At an opposite side of thehinge plate 263 where the first and second hinge axes 251 and 252 areinstalled, the first and second reference pins 261, 262 are installed.At this time, the first and second reference pins 261, 262 are formed sothat a position relation with respect to the first and second hinge axes251 and 252 does not change.

The first hinge frame 270 is rotatably coupled to the first hinge axis251 of the fixing hinge 260. At an end of the first hinge frame 270, afirst hinge hole 271 to which the first hinge axis 251 of the fixinghinge 260 is inserted is provided, and at the center, a place where afirst engaging member 275 may be accommodated is provided. At a firstside wall of the first hinge frame 270 facing the fixing hinge 260, afirst guiding block 272 which may guide moving of a first moving member2130 is provided. At a second side wall which is formed in parallel withthe first side wall of the first hinge frame 270, a first guide slot 273which guides moving of the first support arm 2110 is formed.

A second hinge frame 280 is rotatably coupled to the second hinge axis252 of the fixing hinge 260. At an end of the second hinge frame 280, asecond hinge hole 281 to which the second hinge axis 252 of the fixinghinge 260 is provided, and at the center a place where a second engagingmember 285 may be accommodated is provided. At the first side wall ofthe second hinge frame 280 facing the fixing hinge 260, a second guidingblock 282 which may guide moving of the second moving member 2140 may beprovided. At the second side wall which is formed in parallel with thefirst side wall of the second hinge frame 280, a second guide slot 283which guides moving of the second support arm 2120 is formed.

A locking member 290 constitutes a locking unit along with the first andsecond engaging members 275 and 285. The locking unit may lock the firstbody and the second body 210 and 220 of the foldable device 20 atmultiple positions. For example, the locking unit may lock the first andsecond bodies 210 and 220 at a completely unfolding position (FIG. 20)and a completely folding position (FIG. 21). In addition, the lockingunit may lock the first and second bodies 210 and 220 at a position(inclined position) having a predetermined open angle (i.e., obtuseangle) between the completely unfolding position (FIG. 20) and thecompleted folding position (FIG. 21). The open angle at the inclinedposition may be greater than 90 degrees. The locking unit may lock thefirst and second bodies 210 and 220 at multiple inclined positionsbetween 90 degrees and 180 degrees. For example, the open angle at aninclined position may be 120 degrees.

The locking member 290 is installed at a fixed position, and the firstand second engaging members 275 and 285 are formed to be engaged withthe locking member 290 while rotating along with the first and secondbodies 210, 220. At an outer circumference of the locking member 290,there are many locking units 293 which lock the first and second bodies210, 220 at each of the unfolding position, inclined position, and thefolding position. Therefore, the first and second engaging members 275,285, according to an opened position of the first and second bodies 210,220, are selectively engaged with one of the many locking units 293.

At a side of the locking member 290, there are first and second fixingholes 291, 292 to which the first and second hinge axes 251 and 252 ofthe fixing hinge 260 which passes through the first and second hingeholes 271, 281 of the first and second hinge frames 270, 280 andinwardly protrudes of the first and second hinge frames 270 and 280 maybe inserted. When the first and second hinge axes 251 and 252 of thefixing hinge 260 are inserted to the first and second fixing holes 291,292, the locking member 290 are fixed with respect to the fixing hinge260 regardless of rotation of the first and second bodies 210, 220.

The first and second engaging members 275 and 285 rotate along with thefirst and second bodies 210 and 220 with respect to the first and secondhinge axes 251 and 252. The first and second engaging members 275 and285 are supported by the first and second hinge frames 270 and 280, sothat the first and second engaging members 275 and 285 move in anapproaching direction or distant direction from the locking member 290.The first and second elastic members 276 and 286 add elastic power tothe first and second engaging members 275 and 285 so that the first andsecond engaging members 275 and 285 are in contact with the locking unit293.

At a side of the locking member 290, an interlocking groove 294 isformed where an interlocking bar 2100 is accommodated. The interlockingbar 2100 connects the first hinge frame 270 and the second hinge frame280 so that the first and second hinge frames 270 and 280 aresynchronized and rotated. At both ends of the interlocking bar 2100, thefirst connecting protrusion and the second connecting protrusion 2101and 2102 are formed. The first connecting protrusion 2101 is inserted tothe first connection hole which is formed on the first hinge frame 270,and the second connection hole 2102 is inserted to the second connectionhole 284 which is formed on the second hinge frame 280. When the firstand second connection protrusion 2101 and 2012 of the interlocking bar2100 are combined with the first and second connection holes 284 of thefirst and second hinge frames 270 and 280, the first and second bodies210 and 220 are synchronized and rotated. Accordingly, when one of thefirst and second engaging members 275 and 285 is engaged with thelocking unit 293, the first and second bodies 210 and 220 are locked sothat they are not rotated.

The first support arm 2110 moves the first support wing 212 according tomovement of the first body 210. The second support arm 2120 moves thesecond support wing 222 according to movement of the second body 220. Asdescribed above, the first and second support wings 212 and 222 may movebetween a support position and a receiving position. When the first andsecond bodies 210 and 220 are in an unfolding position, the first andsecond support wings 212 and 222 are positioned at a support position,and when the first and second bodies 210 and 220 are in a foldingposition, the first and second support wings 212 and 222 are positionedat a receiving position. So that the first and second bodies 210 and 220may be used at an inclined position between an unfolding position and afolding position, at a position from an unfolding position to aninclined position, the first and second support wings 212 and 222 aremaintained at a support position, and when they are folded in excess ofthe inclined position, the first and second support wings 212 and 222may be moved to a receiving position. Therefore, a receiving start anglethat the first and second support wings 212 and 222 begin to move from asupport position to a receiving position may be greater than an anglecorresponding to the inclined position. For example, the foldable device20 is used at an open angle (i.e., obtuse angle) greater than 90degrees, and the first and second support wings 212, 222 may be formedso that the first and second support wings 212 and 222 are maintained ata support position in the range of the open angle between 90 degrees and180 degrees.

When the first and second support arms 2110 and 2120 are placed at aposition between an unfolding position and a receiving start positioncorresponding to receiving start angle, the first and second supportarms 2110 and 2120 maintain the first and second support wings 212 and222 at a support position, and move the first and second support wings212, 222 to a receiving position in a folding position in excess of thereceiving start position. To do this, the first and second support arms2110 and 2120 may be formed to rotate around a fixed position withrespect to the first and second hinge axes 251 and 252 and support thefirst and second support wings 212, 222.

To be specific, as illustrated in FIGS. 25, 25B, and 25C, at both endsof the first support arm 2110, there are the first guide pin 2111 andthe first pivot pin 2112, and at both ends of the second support arms2120, there are the second guide pin 2121 and the second pivot pin 2122.The first and second pivot pins 2112 and 2122 are pivotably installed onthe locking member 290. In case of the locking member 290, asillustrated in FIG. 25B, there are first and second pivot holes 295 and296 to which the first and second pivot pins 2112 and 2122 are pivotablyinserted. The first and second guide pins 2111 and 2121 are inserted tothe first and second guide slots 273 and 283 formed respectively at oneside of the first and second hinge frames 270 and 280. The first guidepin 2111 penetrates into the first guide slot 273, extends below thefirst support wing 212, and supports the first support wing 212.Therefore, when the first guide pine 2111 moves by the first guide slot273, the first support wing 212 rotates at the rotation axis 214.

As such, the second guide pin 2121 penetrates into the second guide slot283, extends below the second support wing 222, and supports the secondsupport wings 222. Therefore, when the second guide pin 2121 moves bythe second guide slot 283, the second support wing 222 rotates at therotation axis 224.

The first and second guide slots 273 and 283 provided on one side wallof each of the first and second hinge frames 270 and 280 include asupport section 273 a and a receiving section 273 b (see FIG. 28A). Thesupport section 273 a corresponds to a section from an unfoldingposition to a receiving start position, and the receiving section 273 bcorresponds to a receiving start position to the folding position. Whilethe first and second bodies 210 and 220 rotate from the unfoldingposition of the first and second bodies 210 and 220 to the receivingstart position, the support section 273 a maintains a position at whichthe first and second guide pins 2111 and 2121 of the first and secondsupport arms 2110 and 2120 supports the first and second support wings212 and 222. While the first and second bodies 210 and 220 rotate fromthe receiving start position to the folding position, the first andsecond support arms 2110 and 2120 rotate so that the first and secondguide pins 2111 and 2121 move in a direction in which the first andsecond guide pins 2111, 2121 become distant from the first and secondsupport wings 212 and 222. Then, the first and second support wings 212and 222 move from the support position to the receiving position byself-load.

FIG. 28A illustrates the first support wing 212, when the first andsecond bodies 210, 220 of the foldable device 20 are in an unfoldingposition. The second support wing 222 operates in the same manner as thefirst support wing 212, and FIG. 28A illustrates the first support wing212 only.

Referring to FIG. 28A, the first guide pin 2111 is positioned at thesupport section 273 a of the first guide slot 273, and the first supportwing 212 is supported by the first guide pin 2111 of the first supportarm 2110 and is maintained at a support position. The second supportwing 222 is maintained by the second guide pin 2121 of the secondsupport arm 2120. To be specific, the second guide pin 2121 of thesecond support arm 2120 is positioned at the support section 283 a (seeFIG. 25C) of the second guide slot 283, and the second support wing 222is supported by the second support pin 2121 and maintained at a supportposition. Therefore, the flexible display 240 is supported by the firstand second fixed portions 211 and 221, the first and second supportwings 212 and 222, and a central support member 2150 to be describedlater and, and is maintained to be flat.

In FIG. 28A, when the first and second bodies 210, 220 begin to befolded, the first and second bodies 210, 220 move in a direction whichbecomes distant from the first and second hinge axes 251 and 252 by thephase difference compensation unit. Until the first and the secondbodies 210 and 220 reach a receiving start position, the first andsecond guide pins 251 and 252 are guided by the support section 273 aand 283 a of the second guide slot 273 and 283, and the first and secondsupport arms 2110, 2120 are maintained at a position to support thefirst and second support wings 212, 222.

When the first and second bodies 210 and 220 are folded beyond thereceiving start position, the first and second guide pins 2111 and 2121are guided by the receiving space 273 b and 283 b of the first andsecond guide slots 273 and 283. The first and second support arms 2110and 2120 move in a direction away from the first and second supportwings 212, 222 centering on the first and second pivot pins 2112 and2122. Therefore, the first and second support wings 212 and 222 rotatetoward a bottom surface of the first and second bodies 210 and 220 andform the receiving space 230 (see FIG. 21) within the first and secondbodies 210 and 220. At this time, on an upper surface of the first andsecond support wings 212 and 222, the parts 243 b and 243 d of the thirdportion 243 of the flexible display 240 are fixed, and while the thirdportion 243 of the flexible display 240 is slightly bent toward a bottomsurface of the first and second bodies 210 and 220 along with the firstand second support wings 212 and 222, forms a curved portion 244, and isreceived in the receiving space 230.

The rotation axes 214 and 224 of the first and second support wings 212and 222 move toward the first and second fixed portions 211 and 221along with the slot hole 215 and 225 provided on the side wall 210 a and220 a of the first and second bodies 210 and 220 as illustrated in FIG.28B, and the phase difference between the flexible display 240 and thefirst and second support wings 212 and 222 is reduced or removed. Thatis, so as to reduce or remove the phase difference between the flexibledisplay 240 and the first and second support wings 212 and 222, therotation axes 214 and 224 of the first and second support wings 212 and222 move to a specific position along with the slot holes 215 and 225provided on the side walls 210 a and 220 a of the first and secondbodies 210 and 220. Therefore, distortion of the flexible display 240which occurs when the movement of the flexible display 240 is notrestricted may be prevented, and stress applied on the flexible display240 may be minimized. Here, FIG. 28B is a view illustrating a relationbetween the first support wing and the first guide pin when a foldabledevice is in a folded state according to another exemplary embodiment.

Therefore, in the above exemplary embodiment, when the first and secondsupport wings 212 and 222 move between a support position and areceiving position, the display restriction member which moves the thirdportion 243 of the flexible display 240 along with the first and secondsupport wings 212 and 222 may be embodied by the fixing member 216 whichfixes the part 243 b and 243 d of the third portion 243 of the flexibledisplay 240 on each upper surface of the first and second support wings212 and 222, and also by a pair of first and second slot holes 215 and225 which are formed in each of the first and second bodies 210 and 220and to which a pair of first and second rotation axis 214 and 224 of thefirst and second support wings 212 and 222 is inserted.

A shape of the first and second guide slots 273 and 283 are notrestricted to an example illustrated in FIGS. 28A and 28B. A shape ofthe first and second guide slots 273 and 283 may be different accordingto a position of the first and second pivot holes 295 and 296.

The first and second moving members 2130 and 2140 are installed on afirst sidewall of the first and second hinge frames 270 and 280 to movewith respect to each of the first and second hinge frames 270 and 280.In addition, the first and second moving members 2130 and 2140 areinstalled to move integrally with the first and second bodies 210 and220. Therefore, the first and second moving members 2130, 2140 restricta moving amount with respect to the first and second hinge axes 251 and252 of the first and second bodies 210, 220.

FIG. 25A is a perspective view illustrating the fixing hinge 260 of thehinge unit 250 and first and second restriction slots 2131 and 2141 ofFIG. 23.

Referring to FIG. 25A, there are first and second restriction slots 2131and 2141 on the first and second moving members 2130 and 2140. The firstand second restriction slots 2131 and 2141 have a shape to restrict amoving amount of the first and second bodies 210 and 220 according to arotation angle of the first and second bodies 210 and 220. To the firstand second restriction slots 2131 and 2141, the first and secondreference pins 261 and 262 of the fixing hinge 260 are inserted. In theexemplary embodiment, the first and second restriction slots 2131 and2141 of the first and second moving members 2130 and 2140 and the firstand second reference pins 261 and 262 of the fixing hinge 260 constitutea phase difference compensation unit.

As described above, the first and second support wings 212 and 222, maymove between the support position and the receiving position as thefirst and second bodies 210 and 220 move between the unfolding positionand the folding position. The first and second support wings 212 and 222are rotated by the first and second guide pins 2111 and 2121 of thefirst and second support arms 2110 and 2120 of which an end is rotatablyinstalled on the locking member 290 fixed on the fixing hinge 260, andthe first and second guide slots 273 and 283 formed on a second sidewallof the second hinge frames 270 and 280. Therefore, according to movementof the first and second bodies 210 and 220, so that the first and secondsupport wings 212 and 222 may move between the support position and thereceiving position, an operation unit to operate the first and secondsupport wings 212 and 222 may be embodied by the first and second guideslots 273 and 283 of the first and second hinge frames 270 and 280 whichmove along with the first and second bodies 210 and 220, and the firstand second support arms 2110 and 2120 which rotate with respect to thelocking member 290 and of which movement is restricted by the first andsecond guide slots 273 and 283.

The flexible display 240 is installed on an upper surface of the firstand second bodies 210, 220, including a first portion 241 fixed to thefirst fixed portion 211, a second portion 242 fixed to the second fixedportion 221, and a third portion 243 located between the first portion241 and the second portion 242. The flexible display 240 has beendescribed and will not be further described.

When the first and second bodies 210 and 220 are folded, a pair of slotholes 215 and 225 formed on the first and second bodies 210 and 220 mayprevent distortion of the flexible display 240 which occurs at aconnection portion of the first and second fixed portions 211 and 221and the first and second support wings 212 and 222, and may minimizestress on the flexible display 240. However, in still another exemplaryembodiment, a pair of slot holes may be formed on the first and secondsupport wings, and may form a pair of rotation axis on the first andsecond bodies. Referring to FIGS. 29A and 29B, this configuration isdescribed.

FIG. 29A is a view illustrating a position of a support wing when thefoldable device according to still another exemplary embodiment isunfolding state, and FIG. 29B is a view illustrating a position of asupport wing, when the foldable device according to still anotherexemplary embodiment is folding state.

Referring to FIG. 29A, the rotation axis 214′ is installed on a sidewall 210 a of the first body 210, and the slot hole 215′ is formed on asupport plate 212 a which is extended from the first support wing 212downward. The slot hole 215′ may have a curved shape. In addition, thefirst guide pin 2111 is located on the support space 273 a of the firstguide slot 273, and the first support wing 212 is supported by the firstguide pin 2111 of the first support arm 2110 and is maintained at asupport position. The second support wing 222 is maintained by a supportposition by the second guide pin 2121 which moves by the second guideslot 283. Therefore, the flexible display 240 is supported by the firstand second fixed portions 211 and 221, the first and second supportwings 212 and 222, and the central supporting member 2150 stay flat.

When the first and second bodies 210, 220 are folded, as illustrated inFIG. 29B, the first guide pin 2111 is positioned at the receiving space273 b of the first guide slot 273. Therefore, the first support wing 212rotates downward to a bottom side of the first body 210 and forms areceiving space 230 within the first body 210. In addition, the secondsupport wing 222 is positioned at a receiving space by the second guidepin 2121 which moves by the second guide slot 283. Accordingly, thesecond support wing 222 rotates toward a bottom side of the second body220, and forms the receiving space 230 within the second body 220. Inparticular, on an upper surface of the first and second support wings212 and 222, a part of the third portion 243 of the flexible display 240is fixed. Thus, the third portion of the flexible display 240 is gentlycurved toward a bottom side of the first and second bodies 210 and 220along with the first and second support wings 212 and 222, forms acurved portion, and is received in the receiving space 230.

The first and second slot holes 215′ formed on the first and secondsupport wings 212 and 222 move toward the first and second fixedportions 211 and 221 along with the first and second rotation axis 214′provided on the sidewall 210 a of the first and second bodies 210 and220 as illustrated in FIG. 29B, and mitigate the phase difference whichoccurs between the flexible display 240 and the first and second supportwings 212 and 222. Therefore, distortion of the flexible display 240which occurs when the flexible display 240 is not restricted may beprevented, and stress applied on the flexible display 240 may beminimized.

Accordingly, when a body is folded, the slot holes 115 and 225, whichare disposed on the first and second support portions (i.e., the firstand second bodies 210 and 220) and on the third support portion (i.e.,the first and second support wings 212 and 222), and the rotation axis214 and 214′ disposed on a counter member, may prevent distortion of theflexible display 240 which occurs at a connection portion of the firstand second support portions 211 and 221 and the first and second supportwings 212 and 222, and may minimize stress exerted on the flexibledisplay 240.

As still another exemplary embodiment, as illustrated in FIG. 37, slotholes 215″-1 and 215″-2 may be formed on both of the first and secondbodies which constitute of the first and second support wings 212 and222 and the first and second support portions 211 and 221, and arotation axis 214″ is separately formed to be inserted to the slot holes215″-1 and 215″-2. The second support wing 222 operates in the samemanner as the first support wing 212, and FIG. 37 illustrates the slotholes 215″-1 and 215″-2 which are installed on one side of the firstsupport wing 212 and one side of the first support portion 211.

To be specific, each of the first slot hole 215″-1 and the second slothole is disposed on the first support wing 212 and the second supportwing 222 of the third support portion, the third slot hole 215″-2corresponding to the first slot hole 215″-1 is disposed in the firstsupport portion 211, and the fourth slot hole corresponding to thesecond slot hole is disposed on the second support portion 221 where thesecond support wing 222 is disposed. In addition, the first rotationaxis 214″ of the first slot hole 215″-1 and the third slot hole 215″-2is inserted to the first support wing 212 of the first support portion211 and the third support portion to install the first support portion211 and the third support portion rotatably with each other. Inaddition, the second rotation axis of the second slot hole and thefourth slot hole is inserted to the second support wing 222 of thesecond support portion 221 and the third support portion to install thesecond support portion 221 and the third support portion rotatably witheach other.

FIGS. 30A and 30B are views illustrating that a reinforcing plate isinstalled on a rear side of the flexible display.

Referring to FIGS. 30A and 30B, a reinforcing plate may be disposed at aposition where an end of a fixed portion (e.g., the first fixed portion211) and a support wing (e.g., the first support wing 212) are adjacentto each other, and a rear side of the flexible display areacorresponding to a part of the fixed portion and the support wing.

For example, when the first portion 241 of the flexible display 240 isfixed to the first fixed portion 211 of the first body 210, and thethird portion 243 of the flexible display 240 is fixed on an upper sideof the first support wing 212, a reinforcing plate 2160 may be installedon a rear side of the first fixed portion 211 and the part 243 a of theflexible display 240 which is not fixed on the first support wing 212.Therefore, the reinforcing plate 2160, so as to cover an area near anend of the first fixed portion 211 and a partial area of the firstsupport wing 212, is formed to have a width corresponding to intervalbetween the adhesive portion 217 of the first fixed portion 211 and thefixing member 216 of the first support wing 212, and a lengthcorresponding to the width of the first support wing 212. Thereinforcing plat 2160 may be formed as thin stainless steel plate. FIGS.30A and 30B only illustrate a part of the flexible display 240 which issupported by the first support wing 212, but on the part of the flexibledisplay 240 supported by the second support wing 222, the reinforcingplate 2160 may be installed in the manner in which the part supported bythe first support wing 212 is installed.

The reinforcing plate 2160 has greater stiffness than the flexibledisplay 240, and if the first and second bodies 210 and 220 are in aunfolding position as illustrated in FIG. 30A, when a user presses apart of the flexible display 240 corresponding to a space between thefirst and second fixed portions 211 and 221 and the first and secondsupport wings 212 and 222, the flexible display 240 may be supported notto be bent.

In addition, as illustrated in FIG. 30B, when the first and secondbodies 210 and 220 are in a folding position, the first and secondsupport wings 212 and 222 are inclined downward. When the first andsecond support wings 212 and 222 are rotated in a downward direction,the reinforcing plate 2160 is not extended and is merely bent, andtensile stress which the flexible display 240 which is located on anupper side of the reinforcing plate 2160 receives may be minimized.

When the first and second bodies 210 and 220 of the foldable device 20are in a folding position, the first and second support wings 212 and222 are rotated downward, and the third portion 243 of the flexibledisplay 240 is bent with a predetermined curvature, forming the curvedportion 244. In particular, on the first and second fixed portions 211and 221 of the first and second bodies 210 and 220 and a part of thefirst and second support wings 212 and 222, a curved side correspondingto curving of the flexible display 240 is formed. A method of formingthe curve will be explained in reference to FIGS. 31A and 31B.

FIG. 31A is a view illustrating a case where a curve corresponding tobending of the flexible display is formed on a support wing only, andFIG. 31B is a view illustrating a case where a curve corresponding tobending of the flexible display is formed from a part of the body wherea support wing is installed.

As illustrated in FIG. 31A, the curve corresponding to a bent portion ofthe flexible display 240 may be formed on the first support wing 212only. A curve 2170 is formed on a part of an upper surface of the firstsupport wing 212 which is adjacent to an end of the first fixed portion211. That is, the curve 2170 is formed on an upper side of the rotationaxis 214′ which is a rotation center of the first support wing 212 or apart where the slot hole 215′ is formed. When distance from an end ofthe first fixed portion 211 to a point (P) of the first support wing 212where the curve 2170 ends is Ll, depth of groove 2171 formed by thecurve 2170 is t1.

As illustrated in FIG. 31B, the curve 2170′ corresponding to the bentportion of the flexible display 240 may be extended from a part of anend of the first fixed portion 211 to the first support wing 212.Therefore, a part of the curve 2170′ is formed near an end of the firstfixed portion 211, and remaining part of the curve 2170′ is formed onthe first support wing 212. Therefore, length of the curve formed on thefirst support wing 212 is reduced. When the first support wing 212 is ina horizontal position, horizontal length corresponding to the curve2170′ may be L2. When length of L2 is the same as L1, distance L3 froman end of the first fixed portion 211 to the point (P) of the firstsupport wing 212 where the curve 2170′ ends is less than L2 (L3<L2). Inaddition, depth (t2) of the groove 2171′ formed by the curve 2170′ isless than the groove depth (t1) where the curve 2170 is formed on thefirst support wing 212. That is, t2 is less than t1 (t2<t1).

FIGS. 31A and 31B illustrate and describe the first support wing 212installed on the first body 210, but the second support wing 222installed on the second body 220 may have the same curve as describedabove.

Since the curve 2170′ which corresponds to the bent portion of theflexible display 240 is engaged with the first and second fixed portions211 and 221 and also with the first and second support wings 212 and222, when the first and second bodies 210 and 220 are unfolded, lengthand depth of an area of the flexible display 240 which is not supportedby the first and second support wings 212, 222 may be reduced.

Hereinabove, it is described that, as an example of a displayrestriction member to prevent distortion of the flexible display 240,when the first and second bodies 210 and 220 of the foldable device 20are in a folding position, a case where a part of the third portion 243of the flexible display 240 is fixed to the first and second supportwings 212 and 222, and the rotation axis 214, 224 of the first andsecond support wings 212 and 222 is supported by the slot hole 215, 225are described. However, this is merely exemplary, and when the first andsecond support wings 212 and 222 move to a receiving position, manymethods may be used to prevent distortion of the flexible display 240.

FIG. 32 is a view illustrating an example of a display restrictionmember used for a foldable device according to another exemplaryembodiment.

Referring to FIG. 32, the display restriction member may include aplurality of slot groove 2180 formed on an upper surface of the firstsupport wing 212 and a sliding gel 2181 accommodated on the plurality ofslot groove 2180.

The first support wing 212 is installed on one side of the first fixedportion 211 of the first body 210 rotatably. The first support wing 212may be positioned in a horizontal position and an inclined positiondownward by the operation unit as described above. On the upper surfaceof the first support wing 212, a plurality of slot grooves 2180 areformed. The plurality of slot grooves 2180 are formed on an uppersurface of the first support wing 212 in a parallel manner with apredetermined depth which does not pass the first support wing 210. Theplurality of slot grooves 2180, as illustrated in FIG. 32, may be formedin a width direction of the first support wing 212. The plurality ofslot grooves 2180 may be formed in a length direction of the firstsupport wing 212.

In the plurality of grooves 2180, a sliding gel 2181 is charged. Thesliding gel 2181 may enable a part of the flexible display 240 supportedby the first support wing 212 to slidably move with respect to the firstsupport wing 212. At the same time, fluid having viscosity may enablethe flexible display 240 not to be separated from an upper surface ofthe first support wing 212. For example, the sliding gel 2181 may uselubricating oil or grease having appropriate level of viscosity.Therefore, in the exemplary embodiment of the present application, theflexible display 240 is attached to the first support wing 212 byviscosity of the sliding gel 2181. In addition, the flexible display 240may move in a direction parallel to an upper surface of the firstsupport wing 212.

A part of the flexible display 240 which is not supported by the firstsupport wing 212 is fixed on the first fixed portion 211 of the firstbody 210. In addition, a structure of the first support wing 212 issimilar to the first support wing 212 of the foldable device 20 by theaforementioned exemplary embodiment and thus, detailed explanation willbe omitted.

FIG. 32 illustrates the first support wing 212 only, but the secondsupport wing 222 may be formed in the same manner as the first supportwing 212.

Therefore, according to the above-described exemplary embodiment, thethird portion 243 of the flexible display 240 which is attached to anupper surface of the first and second support wings 212 and 222 slidablymoves with respect to the first and second support wings 212 and 222.Thus, distortion of the flexible display 240 which occurs when foldingthe first and second bodies 210 and 220 may be prevented and stressexerted to the flexible display 240 may be absorbed.

FIG. 33 is a view illustrating another example of the displayrestriction member used for the foldable device according to anotherexemplary embodiment.

Referring to FIG. 33, the display restriction member may include a firststiffener 2190 attached to a rear side of the flexible display 240.

The first support wing 212 is rotatably installed on one side of thefirst fixed portion 211 of the first body 210. The first support wing212 may be positioned in a horizontal state or inclined state downwardby the aforementioned operation unit. The flexible display 240 islocated at an upper side of the first fixed portion 211 and the firstsupport wing 212. The first portion 241 of the flexible display 240corresponding to the first fixed portion 211 is fixed on the first fixedportion 211 by the fixing member 217 such as double-sided tape. A partof the third portion 243 of the flexible display 240 corresponding tothe first support wing 212 is slidably installed on the first supportwing 212. Therefore, when the first and second bodies 210 and 220 arefolded, a part of the third portion 243 of the flexible display 240slides with respect to an upper surface of the first support wing 212.

The first stiffener 2190 according to another exemplary embodiment isfixed on a rear side of the flexible display 240 which slides withrespect to the first support wing 212. The first stiffener 2190 has arelatively high strictness compared to the flexible display 240, andsupports that the flexible display 240 slides with respect to the firstsupport wing 212, and prevents distortion of the flexible display 240.The first stiffener 2190 has a size corresponding to an upper surface ofthe first support wing 212.

In the area of the third portion 243 of the flexible display 240corresponding to the second support wing 222, a second stiffener isinstalled. The second stiffener is attached to a rear side of theflexible display 240 in the same type as the first stiffener 2190illustrated in FIG. 33.

In the above exemplary embodiment, while the first and second stiffener2190 are attached to a lower surface corresponding to the first andsecond support wings 212 and 222 of the third portion 243 of theflexible display 240, the third portion 243 of the flexible display 240slidably moves with respect to the first and second support wings 212and 222, and thus, distortion of the flexible display 240 which occurswhen folding the first and second bodies 210 and 220 may be prevented.

In the meantime, between the first and second bodies 210 and 220 of thefoldable device 20, a central support member 2150 may be installed tosupport a central portion of the third portion 243. Hereinafter,referring to FIGS. 34-36, an example of the central support member whichmay be used for the foldable device according to another exemplaryembodiment will be described.

FIG. 34 is a partial sectional view illustrating a state that thecentral support member 2150 supports the flexible display 240, when thefirst and second bodies 210 and 220 of the foldable device 20 areunfolded according to another exemplary embodiment. FIG. 35 is a partialsectional view indicating a position of the central support member whenthe foldable device is folded according to another exemplary embodiment.FIG. 36 is a perspective view indicating the central support member usedfor the foldable device according to another exemplary embodiment.

Referring to FIG. 34, when the first and second bodies of the foldabledevice 20 are in an unfolding position, the central support member 2150supports the central portion of the third portion 243 of the flexibledisplay 240. To be specific, when the first and second bodies 210 and220 are in an unfolding position, the central support member 2150 isformed to support a part of the flexible display 240 which correspondsto an interval between the first and second support wings 212 and 222.Therefore, when a user adds power to the central portion of the thirdportion 243 of the flexible display 240, the flexible display 240 isstably supported without being pressed downward.

An example of the central support member 2150 is illustrated in FIG. 36.Referring to FIG. 36, the central support member 2150 includes the mainsupport portion 2151 and the sub support portion 2153.

The main support portion 2151 which is in a rectangular bar shape has alength corresponding to width of the flexible display 240. At both sidesof the main support portion 2151, a plurality of engaging grooves 2152where the sub support member 2153 is installed are formed at apredetermined interval. Bottoms of each of a plurality of engaginggrooves 2152 function as a support spot 2152 a to prevent the subsupport portion 2153 from rotating in an opposite direction.

There are two sub support portions 2153 so as to be installed at bothsides of the main support portion 2151. The sub support portion 2153 hasa rectangular bar shape, and has a length corresponding to the mainsupport portion 2151. At one side of the sub support portion 2153, aplurality of engaging grooves 2154 which may be engaged with a pluralityof engaging grooves 2152 of the main support portion 2151 are provided.The engaging groove 2152 of the main support portion 2151 and theengaging groove 2154 of the sub support portion 2153 are coupled by ahinge structure. Therefore, the sub support portion 2153 may be rotatedat a predetermined angle with respect to the main support portion 2151.The rotation of the sub support portion 2153 is restricted by bottom2152 a of the main support portion 2151, and thus, the sub supportportion 2153 may rotate in an upper side with respect to the mainsupport portion 2151 and may not rotate in a downward direction.

Accordingly, when the foldable device 20 having the central supportmember 2150 according to another exemplary embodiment is in an unfoldingstate, as illustrated in FIG. 34, the central support member 2150 islocated at a space between the first and second support wings 212 and222, and supports the flexible display 240, and thus, a user may use thecentral portion of the flexible display 240 stably.

In addition, when the first and second bodies 210 and 220 are in afolding position, as illustrated in FIG. 35, the main support portion2151 of the central support member 2150 moves downward, and two subsupport portions 2153 are in an inclined state so that they are notinterfered with the curved portion of the flexible display 240 which iscurved in a droplet shape.

Therefore, when the first and second bodies 210 and 220 are in anunfolding state, the foldable device 20 having the central supportmember 2150 may stably support the central portion of the flexibledisplay 240, and when the first and second bodies 210 and 220 are in anunfolding state, they are not interfered with the curved portion of theflexible display 240.

The foregoing exemplary embodiments and advantages are merely exemplaryand are not to be construed as limiting. The present teaching can bereadily applied to other types of apparatuses. Also, the description ofthe exemplary embodiments is intended to be illustrative, and not tolimit the scope of the claims, and many alternatives, modifications, andvariations will be apparent to those skilled in the art.

1. A foldable device comprising: a flexible display comprising a firstportion, a second portion, and a third portion disposed between thefirst portion and the second portion; a body comprising a first supportportion which supports the first portion of the flexible display, asecond support portion which supports the second portion of the flexibledisplay, and a third support portion which supports the third portion ofthe flexible display; a hinge comprising a first rotation axis whichconnects the first support portion to the third support portion, and asecond rotation axis which connects the second support portion to thethird support portion; a first slot hole having a curved shape whichshifts the first rotation axis and the second along a first innersurface of the first slot hole when the first support portion rotates;and a second slot hole having the curved shape which shifts the secondrotation axis along a second inner surface of the second slot hole whenthe second support portion rotates.
 2. The foldable device as claimed inclaim 1, wherein the first rotation axis and the second rotation axisallow the first support portion and the second support portion to rotatewith respect to the third support portion when the flexible displaychanges from an open state to a closed state, wherein the first slothole is disposed on the first support portion and the third supportportion and is rotatably coupled with the first rotation axis, andwherein the second slot hole is disposed on the second support portionand the third support portion and is rotatably coupled with the secondrotation axis.
 3. The foldable device as claimed in claim 2, wherein thethird support portion comprises a first support wing rotatably connectedto the first support portion and a second support wing rotatablyconnected to the second support portion.
 4. The foldable device asclaimed in claim 3, wherein the first rotation axis is disposed on bothsides of the first support wing, the second rotation axis is disposed onboth sides of the second support wing, and the first slot hole isdisposed on the first support portion and configured to receive thefirst rotation axis of the first support wing and the second slot holeis disposed on the second support portion and configured to receive thesecond rotation axis of the second support wing.
 5. (canceled)
 6. Thefoldable device as claimed in claim 3, wherein the first slot hole isdisposed on both sides of the first support wing and the second slothole is disposed on both sides of the second support wing, and whereinthe first rotation axis is disposed on the first support portion andinserted to the first slot hole of the first support wing, and thesecond rotation axis is disposed on the second support portion andinserted to the second slot hole of the second support wing. 7.(canceled)
 8. The foldable device as claimed in claim 3, wherein thefirst slot hole is disposed on both sides of the first support wing, thesecond slot hole is disposed on both sides of the second support wing,wherein the foldable device further comprises: a third slot holedisposed on the first support portion which faces the first slot hole ofthe first support wing; and a fourth slot hole disposed on the secondsupport portion which faces the second slot hole of the second supportwing, and wherein the first rotation axis is inserted to the first slothole of the first support wing and the third slot hole of the firstsupport portion, and the second rotation axis is inserted to the secondslot hole of the second support wing and the fourth slot hole of thesecond support portion.
 9. The foldable device as claimed in claim 3,wherein a fixing member which fixes the third portion of the flexibledisplay is fixed on an upper surface of the first support wing and thesecond support wing.
 10. The foldable device as claimed in claim 9,wherein the fixing member comprises a double-sided tape and an adhesive.11. The foldable device as claimed in claim 2, further comprising: afirst reinforcing plate that covers a part of the first support portionand the third support portion, and supports a part of the flexibledisplay; and a second reinforcing plate that covers a part of the secondsupport portion and the third support portion, and supports a part ofthe flexible display.
 12. The foldable device as claimed in claim 11,wherein the first reinforcing plate and the second reinforcing plate arefixed on a rear surface of the flexible display.
 13. The foldable deviceas claimed in claim 3, further comprising: a first guide slot and asecond guide slot; and a first support arm and a second support armwhich allow the first support wing and the second support wing to move,according to movement of the first support portion and the secondsupport portion, between a support position which supports that thethird portion of the flexible display is in a same plane as the firstportion and the second portion, and a receiving position which forms areceiving space to receive a curved third portion of the flexibledisplay between the first support portion and the second supportportion.
 14. The foldable device as claimed in claim 13, wherein thefirst guide slot and the second guide slot move along with the firstsupport portion and the second support portion and the first support armand the second support arm move by the first guide slot and the secondguide slot.
 15. The foldable device as claimed in claim 14, wherein thefirst support arm and the second support arm comprise a first guide pinand a second guide pin which pass through the first guide slot and thesecond guide slot and are extended to a bottom of the first support wingand the second support wing.
 16. The foldable device as claimed in claim3, wherein the third support portion further comprises a central supportmember which supports a central portion of the third portion of theflexible display.